Demolish means “completely destroy,” as a wrecking ball might demolish a building, or as hanging out with one’s parents might, supposedly, demolish a teenager’s reputation.
In casual speech, demolish can also mean “devour,” as a group of hungry teenagers might demolish a pizza. The noun form of demolish is demolition, which often implies destruction by means of explosives. Demolish combines the prefix de-, which can mean “undo,” with the Latin verb moliri, meaning “to build" — which makes sense if you are thinking of 'undoing a building' with explosives!
