Idiom
ward off somethingward off (someone/something)
to try to keep away someone or something that would hurt you.He raised his arm at the elbow to ward off the blow.They have a “No Trespassing” sign out front to ward off anyone who happens by.She often gets headaches, so she carries a bit of fresh ginger wherever she goes to ward them off.
Related vocabulary: fend off someone, stave off something