know

v. & n.
—v. (past knew; past part. known)
1 tr. (often foll. by that, how, what, etc.) a have in the mind; have learnt; be able to recall (knows a lot about cars; knows what to do). b (also absol.) be aware of (a fact) (he knows I am waiting; I think he knows). c have a good command of (a subject or language) (knew German; knows his tables).
2 tr. be acquainted or friendly with (a person or thing).
3 tr. a recognize; identify (I knew him at once; knew him for an American). b (foll. by to + infin.) be aware of (a person or thing) as being or doing what is specified (knew them to be rogues). c (foll. by from) be able to distinguish (one from another) (did not know him from Adam).
4 tr. be subject to (her joy knew no bounds).
5 tr. have personal experience of (fear etc.).
6 tr. (as known adj.) a publicly acknowledged (a known thief; a known fact). b Math. (of a quantity etc.) having a value that can be stated.
7 intr. have understanding or knowledge.
8 tr. archaic have sexual intercourse with.
—n. (in phr. in the know) colloq. well-informed; having special knowledge.
Phrases and idioms:
all one knows (or knows how)
1 all one can (did all he knew to stop it).
2 adv. to the utmost of one's power (tried all she knew). before one knows where one is with baffling speed.
be not to know
1 have no way of learning (wasn't to know they'd arrive late).
2 be not to be told (she's not to know about the party). don't I know it! colloq. an expression of rueful assent. don't you know colloq. or joc. an expression used for emphasis (such a bore, don't you know). for all (or aught) I know so far as my knowledge extends. have been known to be known to have done (they have been known to not turn up). I knew it! I was sure that this would happen. I know what I have a new idea, suggestion, etc. know about have information about. know-all colloq. a person who seems to know everything. know best be or claim to be better informed etc. than others. know better than (foll. by that, or to + infin.) be wise, well-informed, or well-mannered enough to avoid (specified behaviour etc.).
know by name
1 have heard the name of.
2 be able to give the name of. know by sight recognize the appearance (only) of. know how know the way to do something.
know-how n.
1 practical knowledge; technique, expertise.
2 natural skill or invention. know-it-all = know-all.
know-nothing
1 an ignorant person.
2 an agnostic. know of be aware of; have heard of (not that I know of). know one's own mind be decisive, not vacillate. know the ropes (or one's stuff) be fully knowledgeable or experienced. know a thing or two be experienced or shrewd. know what's what have adequate knowledge of the world, life, etc. know who's who be aware of who or what each person is. not if I know it only against my will. not know that ... colloq. be fairly sure that ... not (I don't know that I want to go). not know what hit one be suddenly injured, killed, disconcerted, etc. not want to know refuse to take any notice of. what do you know (or know about that)? colloq. an expression of surprise.
you know colloq.
1 an expression implying something generally known or known to the hearer (you know, the pub on the corner).
2 an expression used as a gap-filler in conversation. you know something (or what)? I am going to tell you something. you-know-what (or -who) a thing or person unspecified but understood. you never know nothing in the future is certain.
Derivatives:
knowable adj. knower n.
Etymology: OE (ge)cnawan, rel. to CAN(1), KEN