From Wiktionary, the free dictionary
From vermek.
-ivermek
- A suffix with infinite productivity that forms verbs from other verbs, adding the meaning of "to do the same action with ease, quickly".
- atmak (“to throw”) + -ivermek → atıvermek (“to throw real quick”)
Dışarı çıkarken çöpü atıver.- When you're going out take out the trash, please.