nut

UK: 'NUT': /ˌɛnjuːˈtiː/; 'nut': /ˈnʌt/

US: /nʌt/

US: 'nut': (nut); 'Nut': (no̅o̅t)

Inflections of 'nut' (v): (⇒ conjugate)

nuts

v 3rd person singular

nutting

v pres p

nutted

v past

nutted

v past p

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

nut /nʌt/   n. 

[countable]
1. Food, Botany a dry fruit made up of a kernel that may be eaten, and enclosed in a woody or leathery shell.
2. Botany the kernel itself.
3. Botany a hard, one-seeded fruit, as the chestnut or the acorn.
4. a block, usually of metal, made with a threaded hole so that it can be screwed down on a bolt to hold together objects through which the bolt passes.
5. Slang Terms a person who is greatly interested in or enthusiastic about something;
   devotee:
   She's a sports nut.
6. Slang Terms
   • a foolish, silly, or eccentric person.
   • an insane person.

Idioms

7. a hard or tough nut to crack:
   • Idioms a difficult problem:
     Getting a tax refund this year is going to be a tough nut to crack.
   • Idioms a person difficult to understand or convince.

WordReference Random House Unabridged Dictionary of American English © 2025

nut  (nut), n., v., nut•ted, nut•ting. 
n. 

1. Food, Botany a dry fruit consisting of an edible kernel or meat enclosed in a woody or leathery shell.
2. Botany the kernel itself.
3. Botany a hard, indehiscent, one-seeded fruit, as the chestnut or the acorn.
4. any of various devices or ornaments resembling a nut.
5. a block, usually of metal and generally square or hexagonal, perforated with a threaded hole so that it can be screwed down on a bolt to hold together objects through which the bolt passes.
6. Slang Terms the head.
7. Slang Terms
   • a person who is very enthusiastic about something;
     buff;
     enthusiast;
     devotee:
     He's a real circus nut.
   • an extremely concerned or zealous person:
     My boss is a nut on double-checking everything.
8. Slang Terms
   • a foolish, silly, or eccentric person.
   • [Offensive.] an insane person;
     psychotic.
9. Slang Terms (vulgar). a testis.
10. Show Business, Informal Terms [Informal.]
    • the operating expenses, usually figured weekly, of a theatrical production or other commercial enterprise;
      a break-even point.
    • the total cost of producing a theatrical production or of forming and opening any new business venture.
11. Music and Dance (in instruments of the violin family)
    • the ledge, as of ebony, at the upper end of the fingerboard, over which the strings pass.
    • the movable piece at the lower end of the bow, by means of which the hairs may be slackened or tightened.
12. Printing en (def. 2).
13. Idioms from soup to nuts. See soup (def. 6).
14. hard nut to crack:
    • Idioms a problem difficult to solve;
      a formidable undertaking.
    • Idioms a person difficult to know, understand, or convince. Also, tough nut to crack. 
15. Slang Terms off one's nut:
    • Idioms [Sometimes Offensive.] foolish, silly, or insane.
    • Idioms confused;
      unreasonable.
    • Idioms mistaken or wrong:
      You're off your nut if you think such a plan can succeed.

v.i. 

16. to seek for or gather nuts:
    to go nutting in late autumn.

• bef. 900; 1900–05 for def. 8b; Middle English nute, Old English hnutu; cognate with Dutch noot, German Nuss, Old Norse hnot; akin to Latin nux

nut′like′, adj. 

Nut  (no̅o̅t), n. [Egyptian Relig.]

1. Eastern Religions the goddess of the sky, sometimes shown as a cow bearing Ra on her back and the stars on her underside.

N.U.T., [Brit.]

1. British Terms National Union of Teachers.

Collins Concise English Dictionary © HarperCollins Publishers::

nut / nʌt/ noun

1. a dry one-seeded indehiscent fruit that usually possesses a woody wall
2. (not in technical use) any similar fruit, such as the walnut, having a hard shell and an edible kernel
3. the edible kernel of such a fruit
4. a person who behaves in a foolish manner
5. a slang word for head1
6. do one's nut ⇒ to be extremely angry; go into a rage
7. off one's nut ⇒ foolish in behaviour
8. mentally disordered
9. a person or thing that presents difficulties (esp in the phrase a toughorhard nut to crack)
10. a small square or hexagonal block, usually metal, with a threaded hole through the middle for screwing on the end of a bolt
11. Also called (US and Canadian): frog the ledge or ridge at the upper end of the fingerboard of a violin, cello, etc, over which the strings pass to the tuning pegs
12. the end of a violin bow that is held by the player
13. another word for en
14. a small usually gingery biscuit
15. a small piece of coal

verb (nuts, nutting, nutted)

1. (intransitive) to gather nuts

Etymology: Old English hnutu; related to Old Norse hnot, Old High German hnuz (German Nuss)USAGE
Using an informal word to refer to mental illness, or people who have mental health problems, can be considered highly insensitive and should be avoided

Collins Concise English Dictionary © HarperCollins Publishers::

NUT abbreviation (in Britain)

1. National Union of Teachers