1 a (usu. foll. by of) awareness or familiarity gained by experience (of a person, fact, or thing) (have no knowledge of that). b a person's range of information (is not within his knowledge).
2 a (usu. foll. by of) a theoretical or practical understanding of a subject, language, etc. (has a good knowledge of Greek). b the sum of what is known (every branch of knowledge).
3 Philos. true, justified belief; certain understanding, as opp. to opinion.
4 = carnal knowledge.
Phrases and idioms:
come to one's knowledge become known to one. to my knowledge
1 so far as I know.
2 as I know for certain.
Etymology: ME knaulege, with earlier knawlechen (v.) formed as KNOW + OE -laeligcan f. lac as in WEDLOCK
Useful english dictionary. 2012.