Two or more individuals engaged in robust and active dialogue about something or things that intentionally make absolutely no sense. In most cases, involves men under the age of 30 or women of any age after two or more glasses of wine.
Jim and Bob spent the entire dinner amusing themselves by talking whack which initially confused and ultimately annoyed their dates.
the act of using sexually explicit language in an attempt to get your partner sexually aroused. Can be done in person or over the phone. (When done over the phone is refered to as Phone Sex.
Couples sometimes try talking dirty to turn one another on:
Guy: I want to f*ck you so hard.
Girl: You make me so horny.