What? What did you say?

in front of, before, ago,

in front (of) / before (in time)

Nothing

what / that thing (used in place of words you can't remember at the moment.)

What?, Huh?

(adverbial particle, dismissive, derogatory) emphasizes disgust, contempt, or otherwise negative feelings of the speaker: whatever

whatchamacallit, X

何: interrogative pronoun; what

何か: something