Q: What do you call a boomerang that doesn’t come back?
A: A stick!

Explanation: That’s just silly!  A boomerang is currently used as a toy but according to some histories it was/ is used for hunting.  Originally it was made of wood but now can be made of plastic or other material.

This joke is funny because you expect a more serious answer and not such a silly answer. Of course if you throw a stick it will not come back.