let alone

WordReference Random House Learner's Dictionary of American English © 2025

a•lone /əˈloʊn/   adj. 

1. separate, apart;
   by oneself:
   [be + ~] alone in the wilderness.
2. to the exclusion of all others or all else:
   [after a noun or pronoun] You can't live by bread alone.
3. [be + ~] unequaled;
   unexcelled.
4. only;
   nothing else being necessary:
   [after a noun] Her name alone was enough to draw a crowd.

adv. 

5. by oneself:
   She lives alone.
6. solely;
   exclusively:
   This glassware is sold by us alone.
7. without aid or help:
   The baby can stand alone.

Idioms

8. Idioms leave or let alone, [leave/let + object + ~] to refrain from bothering or interfering with:
   left him alone with his thoughts.
9. Idioms leave or let well enough alone, to leave things as they are:
   Let's leave well enough alone and stop tinkering.
10. Idioms let alone, not to mention:
    too tired to walk, let alone run.

a•lone•ness, n. [uncountable]

WordReference Random House Learner's Dictionary of American English © 2025

let¹ /lɛt/   v., let, let•ting, n. 
v. 

1. to allow or permit: [~ + object + root form of verb]
   Don't let her see our faces.
   [~ + object]
   Can you come out? No, my parents won't let me.
2. to allow to pass, go, or come:
   [~ + object] He let us into the house.
3. to cause to;
   make:
   [~ + object + root form of verb] to let her know the truth.
4. [~ + object + root form of verb] This word is used in the command forms Let or Let us (or Let's, which is short for Let us):
   • to make a request:
     Let's try to get along, please.
   • to give a command:
     Let me see what's in your hand.
   • to express a warning about someone else doing something:
     If they think they can just take over, just let them try.
   • to make a suggestion:
     Why not let her drive?
   • to express one's indifference to some situation;
     to show that one does not care about something:
     If she wants to gamble, let her do it.
5. to grant the use of for rent or hire:
   [~ + object] to let rooms.
6. to allow to be leased:
   [no object] an apartment to let.

v. 

7. Aeronautics let down:
   • to disappoint or betray: [~ + object + down]
     She really let me down when she didn't come to our party.
     [~ + down + object]
     He let down the whole team.
   • [~ + object + down] to lower:
     He let the car down off the lift.
   • to make (a garment) longer: [~ + down + object]
     Can you let down this dress a few inches?
     [~ + object + down]
     He let the dress down a few inches.
8. let in, to admit: [~ + in + object]
   This place lets in all kinds of people.
   [~ + object + in]
   Let me in.
9. let in on, [~ + object + in + on + object] to allow to share in:
   I'll let you in on a secret.
10. let off:
    • to release like an explosion: [~ + off + object]
      to let off steam.
      [~ + object + off]
      to let steam off.
    • to excuse from work or responsibility: [~ + object + off]
      The boss let us off early.
      [~ + off + object]
      The boss let off his workers early.
    • to release with little or no punishment: [~ + object + off]
      The judge let him off with probation.
      [~ + off + object]
      That judge lets off too many criminals.
11. let on:
    • to reveal: [~ + on + (that) clause]
      He didn't let on that he knew about the party.
      [no object]
      She knew where they were going, but she never let on.
      [~ + on + about + object]
      She never let on about it.
    • [~ + on + (that) clause] to pretend:
      He tried to let on that he didn't care.
12. let out:
    • [~ + out + object] to make known;
      express:
      He let out a doubt.
    • to release from confinement, restraint, etc.: [~ + object + out]
      to let air out of a tire.
    • to alter (a garment) so as to make larger or looser: [~ + out + object]
      to let out a dress a few inches.
      [~ + object + out]
      to let a dress out a few inches.
    • [no object] to be finished or dismissed:
      School lets out in May.
13. let up, [no object]
    • to grow less powerful;
      lessen;
      abate;
      diminish:
      The hurricane let up gradually.
    • to cease;
      stop:
      At last, the rain is letting up.
14. let up on, [~ + up on + object] to become more lenient with;
    to treat less strictly:
    Let up on her; she's just a child.

n. [countable* usually singular]

15. British Terms a housing rental.

Idioms

16. Idioms let be, [~ + object + be] to refrain from interfering with or bothering:
    Those boys wouldn't let him be, with their constant teasing.

let go:

• [~ + object + go] to allow to escape:
  She let the fish go because it was too small to keep.
• to stop holding on to: [~ + go + of + object]
  let go of the rope and fell.

[no object]

Hold on, don't let go.

let oneself in for, [~ + object + in + for] to allow oneself to become involved in:

He didn't know what he was letting himself in for when he started the new job.

Idioms, Informal Terms let (someone) have it, [~ + object + have it] [Informal.] to attack;
assault.

let² /lɛt/   n. [countable]

1. Sport (in tennis, badminton, etc.) any shot or action that must be replayed, esp. an otherwise valid serve that has hit the top of the net.

-let, suffix. 

1. • -let is attached to a noun to form a noun that is a smaller version of the original noun or root:
     book + -let → booklet (= a smaller book);
     pig + -let → piglet (= a smaller pig).
   • -let is also attached to a noun to form a noun that is a band, ornament, or article of clothing worn on the part of the body mentioned:
     ankle + -let → anklet (= piece of clothing like a sock worn on the ankle);
     wrist + -let → wristlet (= ornament like a bracelet worn on the wrist).

WordReference Random House Unabridged Dictionary of American English © 2025

a•lone  (ə lōn′), adj. (used predicatively)

1. separate, apart, or isolated from others:
   I want to be alone.
2. to the exclusion of all others or all else:
   One cannot live by bread alone.
3. unique;
   unequaled;
   unexcelled:
   He is alone among his peers in devotion to duty.
4. leave alone:
   • to allow (someone) to be by himself or herself:
     Leave him alone--he wants to rest.
   • to refrain from annoying or interfering with:
     The youngsters wouldn't leave the dog alone, and he finally turned on them.
5. let alone:
   • to refrain from annoying or interfering with.
   • not to mention:
     He was too tired to walk, let alone run.
6. let well enough alone, to be satisfied with the existing situation;
   refrain from attempting to change conditions:
   Marriages are often destroyed by relatives who will not let well enough alone.

adv. 

7. solitarily;
   solely:
   She prefers to live alone.
8. only;
   exclusively.
9. without aid or help:
   The baby let go of the side of the crib and stood alone.

• Middle English al one all (wholly) one 1250–1300

a•lone′ness, n. 
Synonyms

• 1. single, solitary; unaccompanied, unattended.
  Alone, lone, lonely, lonesome all imply being without companionship or association.
  Alone is colorless unless reinforced by all;
  it then suggests solitariness or desolation:
  alone in the house; all alone on an island.
  Lone is somewhat poetic or is intended humorously:
  a lone sentinel.
  Lonely implies a sad or disquieting feeling of isolation.
  Lonesome connotes emotion, a longing for companionship.

Antonyms

• 1. accompanied.

Usage

4, 5. See leave¹. 

WordReference Random House Unabridged Dictionary of American English © 2025

let¹  (let), v., let, let•ting, n. 
v.t. 

1. to allow or permit:
   to let him escape.
2. to allow to pass, go, or come:
   to let us through.
3. to grant the occupancy or use of (land, buildings, rooms, space, etc., or movable property) for rent or hire (sometimes fol. by out).
4. to contract or assign for performance, usually under a contract:
   to let work to a carpenter.
5. to cause to;
   make:
   to let one know the truth.
6. (used in the imperative as an auxiliary expressive of a request, command, warning, suggestion, etc.):
   Let me see. Let us go. Just let them try it!

v.i. 

7. to admit of being rented or leased:
   The apartment lets for $100 per week.
8. let alone. See alone (def. 5).
9. Idioms let be:
   • to refrain from interference.
   • to refrain from interfering with.
10. Aeronautics let down:
    • to disappoint;
      fail.
    • to betray;
      desert.
    • to slacken;
      abate:
      We were too near success to let down in our efforts.
    • to allow to descend slowly;
      lower.
    • Aeronautics (of an airplane) to descend from a higher to a lower altitude preparatory to making an approach and landing or a similar maneuver.
11. Idioms let go. See go (def. 82).
12. let in:
    • to admit.
    • to involve (a person) in without his or her knowledge or permission:
      to let someone in for a loss.
    • Also, let into. to insert into the surface of (a wall or the like) as a permanent addition:
      to let a plaque into a wall.
    • Also, let in on. to share a secret with;
      permit to participate in.
13. let off:
    • to release by exploding.
    • to free from duty or responsibility;
      excuse.
    • to allow to go with little or no punishment;
      pardon:
      The judge let off the youthful offender with a reprimand.
14. let on:
    • to reveal one's true feelings:
      She was terrified at the prospect, but didn't let on.
    • to pretend:
      They let on that they didn't care about not being invited, but I could tell that they were hurt.
15. let out:
    • to divulge;
      make known.
    • to release from confinement, restraint, etc.
    • to enlarge (a garment).
    • to terminate;
      be finished;
      end:
      When does the university let out for the summer?
    • to make (a let-out fur or pelt).
16. let someone have it, [Informal.] to attack or assault, as by striking, shooting, or rebuking:
    The gunman threatened to let the teller have it if he didn't move fast.
17. let up:
    • to slacken;
      diminish;
      abate:
      This heat wave should let up by the end of the week.
    • to cease;
      stop:
      The rain let up for a few hours.
18. let up on, to treat less severely;
    be more lenient with:
    He refused to let up on the boy until his grades improved.

n. 

19. British Terms a lease.

• bef. 900; Middle English leten, Old English lǣtan; cognate with Dutch laten, German lassen, Old Norse lāta, Gothic lētan; akin to Greek lēdeîn to be weary, Latin lassus tired. See late

Synonyms

• 1. See allow. 
• 1. suffer, grant.
• 3. lease, rent, sublet, hire.

Antonyms

• 1. prevent.

Usage

Let us is used in all varieties of speech and writing to introduce a suggestion or a request:
Let us consider all the facts before deciding.
The contracted form let's occurs mostly in informal speech and writing:
Let's go.
Let's not think about that right now.
Perhaps because let's has come to be felt as a word in its own right rather than as the contraction of let us, it is often followed in informal speech and writing by redundant or appositional pronouns:
Let's us plan a picnic.
Let's you and I (or me) get together tomorrow.
Both Let's you and me and Let's you and I occur in the relaxed speech of educated speakers. The former conforms to the traditional rules of grammar; the latter, nonetheless, occurs more frequently. See also leave¹. 

let²  (let), n., v., let•ted or let, let•ting. 
n. 

1. Sport (in tennis, badminton, etc.) any play that is voided and must be replayed, esp. a service that hits the net and drops into the proper part of the opponent's court.
2. Law [Chiefly Law.] an impediment or obstacle:
   to act without let or hindrance.

v.t. 

3. [Archaic.] to hinder, prevent, or obstruct.

• bef. 900; Middle English letten (verb, verbal), lette (noun, nominal; derivative of the verb, verbal), Old English lettan (verb, verbal), derivative of læt slow, tardy, late; cognate with Old Norse letja to hinder

-let, 

1. a diminutive suffix attached to nouns (booklet;
   piglet;
   ringlet), and, by extraction from bracelet, a suffix denoting a band, piece of jewelry, or article of clothing worn on the part of the body specified by the noun (anklet;
   wristlet).

• Latin -ellus diminutive suffix; compare -elle, chaplet) + -et -et
• Latin -āle, neuter of -ālis -al¹ (compare bracelet) or
• Middle French -elet, equivalent. to -el (
• Middle English -let, -lette

Collins Concise English Dictionary © HarperCollins Publishers::

alone / əˈləʊn/ adjective , adverb (postpositive)

1. apart from another or others; solitary
2. without anyone or anything else: one person alone could lift it
3. without equal; unique: he stands alone in the field of microbiology
4. to the exclusion of others; only: she alone believed him
5. leave alone, leave be, let alone, let be ⇒ to refrain from annoying or interfering with
6. leave well alone, leave well enough alone, let well alone, let well enough alone ⇒ to refrain from interfering with something that is satisfactory
7. let alone ⇒ much less; not to mention: they can't afford a meal out, let alone a holiday

Etymology: Old English al one, literally: all (entirely) one

Collins Concise English Dictionary © HarperCollins Publishers::

let / lɛt/ verb (lets, letting, let)(tr; usually takes an infinitive without to or an implied infinitive)

1. to permit; allow: she lets him roam around
2. (imperative or dependent imperative) used as an auxiliary to express a request, proposal, or command, or to convey a warning or threat: let's get on, just let me catch you here again!
3. (in mathematical or philosophical discourse) used as an auxiliary to express an assumption or hypothesis: let "a" equal "b"
4. used as an auxiliary to express resigned acceptance of the inevitable: let the worst happen
5. to allow the occupation of (accommodation) in return for rent
6. to assign (a contract for work)
7. to allow or cause the movement of (something) in a specified direction: to let air out of a tyre
8. to utter: to let a cry
9. let alone ⇒ (conjunction) much less; not to mention: I can't afford wine, let alone champagne
10. let be, leave alone, leave be ⇒ to refrain from annoying or interfering with: let the poor cat alone
11. let go ⇒
    See go159
12. let loose ⇒ to set free
13. to make (a sound or remark) suddenly: he let loose a hollow laugh
14. to discharge (rounds) from a gun or guns: they let loose a couple of rounds of ammunition

noun

1. the act of letting property or accommodation: the majority of new lets are covered by the rent regulations

Etymology: Old English lǣtan to permit; related to Gothic lētan, German lassen

let / lɛt/ noun

1. an impediment or obstruction (esp in the phrase without let or hindrance)
2. a minor infringement or obstruction of the ball, requiring a point to be replayed
3. the point so replayed

verb (lets, letting, letted, let)

1. (transitive) to hinder; impede

Etymology: Old English lettan to hinder, from læt late; related to Old Norse letja