'ward off' definitions:

Definition of 'ward off'

(from WordNet)
verb
Prevent the occurrence of; prevent from happening; "Let's avoid a confrontation"; "head off a confrontation"; "avert a strike" [syn: debar, forefend, forfend, obviate, deflect, avert, head off, stave off, fend off, avoid, ward off]
verb
Avert, turn away, or repel; "Ward off danger"