know

UK: /ˈnəʊ/ US: /noʊ/ ,(nō; Scot.nō, nou)

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

knows

v 3rd person singular

knowing

v pres p

knew

v past

known

v past p

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

know¹ /noʊ/   v., knew/nu, nyu/  known/noʊn/  know•ing, n. 
v. [not: be + ~-ing]

1. to perceive or understand as fact or truth;
   to have in the mind clearly and with certainty: [~ + object]
   I don't know your name.
   [~ + (that) clause]
   She knows that he is the crook.
   [~ + about + object]
   She knows about your bad habits.
2. to have (something) fixed in the mind or memory:
   [~ + object] to know a poem by heart.
3. [~ + object] to be acquainted or familiar with:
   I know the mayor well. I knew my way around town fairly well.
4. to understand from experience or practice:
   [~ + how clause] knows how to make gingerbread.
5. to be able to distinguish:
   [~ + object + from + object] old enough to know right from wrong
6. to recognize:
   [~ + object] I'd know her if I saw her again.
7. (of a language) to be able to speak:
   [~ + object] He knows Swahili, Spanish, and Swedish.
8. know of, [~ + of + object] to have heard about:
   Do you know of any computer stores in this neighborhood?

Idioms

9. Idioms in the know, in possession of special knowledge or information;
   well-informed.

know•a•ble, adj. 

WordReference Random House Unabridged Dictionary of American English © 2025

know¹  (nō), v., knew, known, know•ing, n. 
v.t. 

1. to perceive or understand as fact or truth;
   to apprehend clearly and with certainty:
   I know the situation fully.
2. to have established or fixed in the mind or memory:
   to know a poem by heart; Do you know the way to the park from here?
3. to be cognizant or aware of:
   I know it.
4. be acquainted with (a thing, place, person, etc.), as by sight, experience, or report:
   to know the mayor.
5. to understand from experience or attainment (usually fol. by how before an infinitive):
   to know how to make gingerbread.
6. to be able to distinguish, as one from another:
   to know right from wrong.
7. [Archaic.] to have sexual intercourse with.

v.i. 

8. to have knowledge or clear and certain perception, as of fact or truth.
9. to be cognizant or aware, as of some fact, circumstance, or occurrence;
   have information, as about something.
10. Idioms know the ropes, [Informal.] to understand or be familiar with the particulars of a subject or business:
    He knew the ropes better than anyone else in politics.

n. 

11. the fact or state of knowing;
    knowledge.
12. Idioms in the know, possessing inside, secret, or special information.

• bef. 900; Middle English knowen, knawen, Old English gecnāwan; cognate with Old High German -cnāhan, Old Norse knā to know how, be able to; akin to Latin (g)nōvī, Greek gignó̄skein. See gnostic, can¹

know′er, n. 
Synonyms

• 1. Know, comprehend, understand imply being aware of meanings. To know is to be aware of something as a fact or truth:
  He knows the basic facts of the subject. I know that he agrees with me.
  To comprehend is to know something thoroughly and to perceive its relationships to certain other ideas, facts, etc. To understand is to be fully aware not only of the meaning of something but also of its implications:
  I could comprehend all he said, but did not understand that he was joking.

know²  (nō, nou), n. [Scot. and North Eng.]

1. Scottish Terms knoll¹.

Collins Concise English Dictionary © HarperCollins Publishers::

know / nəʊ/ verb (knows, knowing, knew / njuː/, known / nəʊn/)(mainly tr)

1. (also intr; may take a clause as object) to be or feel certain of the truth or accuracy of (a fact, etc)
2. to be acquainted or familiar with: she's known him five years
3. to have a familiarity or grasp of, as through study or experience: he knows French
4. (also intr; may take a clause as object) to understand, be aware of, or perceive (facts, etc): he knows the answer now
5. (followed by how) to be sure or aware of (how to be or do something)
6. to experience, esp deeply: to know poverty
7. to be intelligent, informed, or sensible enough (to do something)
8. (may take a clause as object) to be able to distinguish or discriminate
9. to have sexual intercourse with
10. know what's what ⇒ to know how one thing or things in general work
11. you never know ⇒ things are uncertain

noun

1. in the know ⇒ aware or informed

Etymology: Old English gecnāwan; related to Old Norse knā I can, Latin noscere to come to know

ˈknowable adjective