"Confab" is short for "confabulate", which means having an informal get-together discussion or conversation. Nowadays it usually means a low-key conference, i.e. an off-site business meeting without the suits & ties.
I'm not sure my vote counts since I have yet to make it to a confab, but I'm with Gary. I'm pretty sure I've never heard confabulate in a sentence outside of this group either.
