Everything that matters; the only thing of importance.

(modal, set phrase) Generally, all things considered / Altogether

Very nearly; everything short of.

(somewhat dated) Very tired. / (chiefly UK) With everything included. / (poker) Having no further stake to wager, but remaining active in a hand.

(poker) A hand where at least one player bets all of his or her chips. / (poker) A player who is all in.

Alternative form of all in

Alternative form of all in

Alternative form of all in

(emphatic) Not in the least.

(idiomatic) Used similarly to you're welcome, as a conventional reply to an expression of gratitude. / (idiomatic) Don't worry about it (response to worry or an apology)