Yacks

Antonyms for yacks:

be quiet, be modest, deprecate.

Synonyms for yacks:

prate (verb)

blab, boast, brag, chat, clash, clatter, drivel, gabble, jabber, talk, utter, tongue, prattle. talk, runon.

shoot the breeze (verb)

bs, chatter, gab, palaver, prate, prattle, schmooze, yack, yap, chew the fat, shoot the bull, run off at the mouth.