to avoid doing something that you were planning to do
My friend copped out from our plan to go to to the beach for the day.
Dangerous Animals in the World
Although they are relatively shy and dont generally attack humans, when they do, things can get messy. Boomslang venom is a hemotoxin that disables blood clotting. In others words, its victims slowly die as they bleed out from every pore in their body.