lifter vs thief

lifter and thief both are nouns.

Word	Noun	Adjective	Verb	Adverb
lifter	Yes	No	No	No
thief	Yes	No	No	No

As nouns, thief is a hypernym of lifter; that is, thief is a word with a broader meaning than lifter:

lifter: a thief who steals goods that are in a store
thief: a criminal who takes property belonging to someone else with the intention of keeping it or selling it

Other hypernyms of lifter include stealer.

lifter (noun)	thief (noun)
an athlete who lifts barbells	a criminal who takes property belonging to someone else with the intention of keeping it or selling it
a thief who steals goods that are in a store