It is only known to God; it is unknown to people. / (often modifying a parenthetic concession) It is known unto God; it is certainly true.

(informal, idiomatic) Despite the addressee's belief that the speaker was unaware of something, the speaker, in fact, was already aware.

(idiomatic, dialect, slang) Indicates agreement, approval, encouragement.

Alternative form of God knows.

Third-person singular simple present indicative form of know someone

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

Alternative form of God knows

Alternative form of God knows

Third-person singular simple present indicative form of know better

plural of need-to-know