deadlift vs weightlifting

deadlift and weightlifting both are nouns.

Word	Noun	Adjective	Verb	Adverb
deadlift	Yes	No	No	No
weightlifting	Yes	No	No	No

As nouns, weightlifting is a hypernym of deadlift; that is, weightlifting is a word with a broader meaning than deadlift:

deadlift: a weight training exercise in which a loaded barbell is lifted off the ground to the hips, then lowered back to the ground
weightlifting: bodybuilding by exercise that involves lifting weights

Other hypernyms of deadlift include weightlift.

deadlift (noun)	weightlifting (noun)
a weight training exercise in which a loaded barbell is lifted off the ground to the hips, then lowered back to the ground	bodybuilding by exercise that involves lifting weights