motion or being carried down from, away, or off:
deplane (= move down or off a plane); descend ( = move or go down);
reversing or undoing the effects of an action:
deflate (= reverse the flow of air out of something); dehumanize (= reverse the positive, humanizing effects of something);
taking out or removal of a thing:
decaffeinate ( = take out the caffeine from something); declaw (= remove the claws of an animal);
finishing or completeness of an action:
defunct ( = completely non-functioning); despoil ( = completely spoil