WordNet (r) 3.0 (2006):

idle talk
    n 1: idle or foolish and irrelevant talk [syn: prate,
         prattle, idle talk, blether, chin music]

Moby Thesaurus II by Grady Ward, 1.0:

55 Moby Thesaurus words for "idle talk":
   babble, babblement, back-fence gossip, bavardage, bibble-babble,
   blab, blabber, blah-blah, blather, blether, blethers, cackle,
   caquet, caqueterie, chat, chatter, chitchat, chitter-chatter,
   clack, clatter, gab, gabble, gas, gibber, gibble-gabble, gossip,
   gossiping, gossipmongering, gossipry, groundless rumor, guff,
   hot air, jabber, mere talk, natter, newsmongering, nonsense talk,
   palaver, piece of gossip, prate, prating, prattle, prittle-prattle,
   story, tale, talebearing, taletelling, talk, talkee-talkee, tattle,
   tittle-tattle, twaddle, twattle, yak, yakkety-yak