ward off vs preclude

ward off and preclude both are verbs.

Word	Noun	Adjective	Verb	Adverb
ward off	No	No	Yes	No
preclude	No	No	Yes	No

As verbs, preclude is a hypernym of ward off; that is, preclude is a word with a broader meaning than ward off:

ward off: prevent the occurrence of; prevent from happening; to protect from or to keep away anything undesirable; to ward off
preclude: keep from happening or arising; make impossible

Other hypernyms of ward off include forbid, foreclose, forestall, prevent.

ward off (verb)	preclude (verb)
avert, turn away, or repel	keep from happening or arising; make impossible
prevent the occurrence of; prevent from happening; to protect from or to keep away anything undesirable; to ward off	make impossible, especially beforehand