kill a fish

to evacuate one's bowels (i.e. to take a shit ) esp. when one expects it will be particularly foul.

Sam: I need to go kill a fish.
Cam: Huh?
Sam: You know, drop the kids off at the pool, feed the alligators, give birth to a new politician?
Cam: take a shit?
Sam: Isn't that what I said?

by cyberpope67,BC,Canada August 12, 2008