what

let's see; what have we got here

Nothing

which (of three or more) / which one /

having a comeback or excuse for everything one is told, being smart in the sense of having a smart mouth

(idiomatic) just as [someone] says

as a matter of fact; to tell the truth

saying as much as one wants (usually complaints)

(idiomatic) needless to say, goes without saying

(idiomatic) silence is golden, better left unsaid