1. yackety-yak - Noun
2. yackety-yak - Verb
yackety-yak (uncountable)
(slang) prolonged chatter; uninterrupted, idle talk; gossip
yackety-yak (third-person singular simple present yackety-yaks, present participle yackety-yakking, simple past and past participle yackety-yakked)
(intransitive, slang) To talk pointlessly and uninterruptedly.