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definitions

know

1
[noh]
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SEE MORE SYNONYMS FOR know ON THESAURUS.COM

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

verb (used without object), knew, known, know·ing.

to have knowledge or clear and certain perception, as of fact or truth.
to be cognizant or aware, as of some fact, circumstance, or occurrence; have information, as about something.

noun

the fact or state of knowing; knowledge.

Idioms

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

1
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 Latin (g)nōvī, Greek gignṓskein. See gnostic, can1
Related formsknow·er, noun

Synonyms for know

SEE MORE SYNONYMS FOR know ON THESAURUS.COM
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.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for in the know

knowledgeable, learned, abreast, well-rounded, sensible, experienced, wise, conscious, brilliant, intelligent, discerning, informed, sophisticated, appreciative, perceptive, conversant, well-informed, smart, insightful, educated
British Dictionary definitions for in the know

know

verb knows, knowing, knew (njuː) or known (nəʊn) (mainly tr)

(also intr; may take a clause as object) to be or feel certain of the truth or accuracy of (a fact, etc)
to be acquainted or familiar withshe's known him five years
to have a familiarity or grasp of, as through study or experiencehe knows French
(also intr; may take a clause as object) to understand, be aware of, or perceive (facts, etc)he knows the answer now
(foll by how) to be sure or aware of (how to be or do something)
to experience, esp deeplyto know poverty
to be intelligent, informed, or sensible enough (to do something)she knew not to go home yet
(may take a clause as object) to be able to distinguish or discriminate
archaic to have sexual intercourse with
I know what I have an idea
know what's what to know how one thing or things in general work
you know informal a parenthetical filler phrase used to make a pause in speaking or add slight emphasis to a statement
you never know things are uncertain

noun

in the know informal aware or informed
Derived Formsknowable, adjectiveknower, noun

Word Origin for know

Old English gecnāwan; related to Old Norse knā I can, Latin noscere to come to know
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
Word Origin and History for in the know

know

v.

Old English cnawan (class VII strong verb; past tense cneow, past participle cnawen), "to know, perceive; acknowledge, declare," from Proto-Germanic *knew- (cf. Old High German bi-chnaan, ir-chnaan "to know"), from PIE root *gno- "to know" (cf. Old Persian xšnasatiy "he shall know;" Old Church Slavonic znati, Russian znat "to know;" Latin gnoscere; Greek *gno-, as in gignoskein; Sanskrit jna- "know"). Once widespread in Germanic, this form is now retained only in English, where however it has widespread application, covering meanings that require two or more verbs in other languages (e.g. German wissen, kennen, erkennen and in part können; French connaître, savoir; Latin novisse, cognoscere; Old Church Slavonic znaja, vemi). The Anglo-Saxons used two distinct words for this, witan (see wit) and cnawan.

Meaning "to have sexual intercourse with" is attested from c.1200, from the Old Testament. To not know one's ass from one's elbow is from 1930. To know better "to have learned from experience" is from 1704. You know as a parenthetical filler is from 1712, but it has roots in 14c. To know too much (to be allowed to live, escape, etc.) is from 1872. As an expression of surprise, what do you know attested by 1914.

know

n.

"inside information" (as in in the know), 1883; earlier "fact of knowing" (1590s), from know (v.).

Online Etymology Dictionary, © 2010 Douglas Harper
Idioms and Phrases with in the know

in the know

Privy to special or secret information, as in Not too many people are in the know about this project. [Late 1800s]

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.