You've probably seen the word 回る, which means "to revolve." This word is similar, except for you're doing the turning/rotating action on something else. You can simply say to turn something or to rotate something when answering this question, but be sure to think of yourself actually turning/rotating something. Remember this by using the す on the end. You've taken your friend Sue and put her on a stick. You're rotating her over a fire on a spit because you're a sick cannibal.