Definitions:

1. Implies a prolonged or excessive conversation. VERB
   • She couldn't stop the incessant yack of her chatty coworker.
2. Refers to idle talk or gossip, particularly about other people's personal affairs or rumors. VERB
   • They spent the entire lunch break yacking about their coworker's relationships.
3. To talk or chat at length, often in a rambling or tedious manner. VERB
   • I could hear the distant yack of my neighbors arguing next door.

Synonyms:

• cackle
• chatter
• jaw
• ramble
• rattle on
• run off at the mouth
• talk a lot
• yack away
• yak
• yap away