loan shark vs usurer

loan shark and usurer both are nouns.

Word	Noun	Adjective	Verb	Adverb
loan shark	Yes	No	No	No
usurer	Yes	No	No	No

As nouns, loan shark and usurer are synonyms defined as:

loan shark and usurer: someone who lends money at excessive rates of interest

Other synonyms of loan shark include moneylender, shylock.

loan shark (noun)	usurer (noun)
someone who lends money at excessive rates of interest	someone who lends money at excessive rates of interest