[ noh ]
See synonyms for: knowknewknowingknown on

verb (used with object),knew, known, know·ing.
  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?

  1. to be cognizant or aware of: I know it.

  2. be acquainted with (a thing, place, person, etc.), as by sight, experience, or report: to know the mayor.

  3. to understand from experience or attainment (usually followed by how before an infinitive): to know how to make gingerbread.

  4. to be able to distinguish, as one from another: to know right from wrong.

  5. Archaic. to have sexual intercourse with.

verb (used without object),knew, known, know·ing.
  1. to have knowledge or clear and certain perception, as of fact or truth.

  2. to be cognizant or aware, as of some fact, circumstance, or occurrence; have information, as about something.

  1. the fact or state of knowing; knowledge.

Idioms about know

  1. in the know, possessing inside, secret, or special information.

  2. 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.

Origin of know

First recorded before 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 Greek gignṓskein, Latin (g)nōscere, Sanskrit jñātá “known”; see also can1, gnostic

Other words from know

  • knower, noun

Words Nearby know

Other definitions for know (2 of 2)

[ noh, nou ]

nounScot. and North England. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use know in a sentence

British Dictionary definitions for know


/ (nəʊ) /

verbknows, knowing, knew (njuː) or 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

  1. to have a familiarity or grasp of, as through study or experience: he knows French

  2. (also intr; may take a clause as object) to understand, be aware of, or perceive (facts, etc): he knows the answer now

  3. (foll by how) to be sure or aware of (how to be or do something)

  4. to experience, esp deeply: to know poverty

  5. to be intelligent, informed, or sensible enough (to do something): she knew not to go home yet

  6. (may take a clause as object) to be able to distinguish or discriminate

  7. archaic to have sexual intercourse with

  8. I know what I have an idea

  9. know what's what to know how one thing or things in general work

  10. you know informal a parenthetical filler phrase used to make a pause in speaking or add slight emphasis to a statement

  11. you never know things are uncertain

  1. in the know informal aware or informed

Origin of know

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

Derived forms of know

  • knowable, adjective
  • knower, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with know


In addition to the idioms beginning with know

  • know all the answers
  • know a thing or two
  • know beans
  • know better
  • know by heart
  • know by sight
  • know enough to come in out of the rain
  • know from Adam
  • know if one is coming or going
  • know it all
  • know like a book
  • know one's own mind
  • know one's place
  • know one's stuff
  • know one's way around
  • know only too well
  • know the ropes
  • know the score
  • know where one stands
  • know which side of one's bread is buttered

also see:

  • before you know it
  • (know) by heart
  • come in out of the rain, know enough to
  • coming or going, know if one's
  • for all (I know)
  • god knows
  • (know) inside out
  • in the know
  • it takes one to know one
  • left hand doesn't know what right hand is doing
  • not know beans
  • not know from Adam
  • not know where to turn
  • not know which way to jump
  • thing or two, know
  • what do you know
  • what have you (who knows what)
  • which is which, know
  • you know

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.