(ditransitive) To inform (someone) (of something).

(idiomatic) as it is already known.

Ignorant; characterized by foolish denial of facts or beliefs in that which is not true.

An ignorant person; one who lacks knowledge.

plural of know-nothing

Third-person singular simple present indicative form of know someone

(set phrase) To recognize that a statement or belief is false or doubtful. / (set phrase) To understand that certain behavior is wrongful, futile, or inappropriate.

(Ireland, dated) God knows; nobody knows / (Ireland, dated) God knows; of course, certainly, nobody could doubt

plural of Know-Nothing

Alternative form of you know what