1) Bull session 2) Causerie 3) Chat 4) Chinfest 5) Chitchat 6) Gab 7) Gossip 8) Klatch 1) Causerie 2) Chat 3) Chatty gathering 4) Chatty get-together 5) Chin-wag 6) Chin-wagging 7) Chitchat 8) Coffee klatsch, typically 9) Confab 10) Confabulation 11) Conversation of a sort 12) Conversational gathering 13) Gathering with much rapping 14) Gossip 15) Informal chatter 16) Lot of yakking 17) Rap session 
Gabfest is American slang for a gathering for talk, a prolonged conversation.