shoplifter vs thief

shoplifter and thief both are nouns.

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

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

shoplifter: 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 shoplifter include stealer.

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