mercenary vs soldier of fortune

mercenary and soldier of fortune both are nouns.

Word	Noun	Adjective	Verb	Adverb
mercenary	Yes	Yes	No	No
soldier of fortune	Yes	No	No	No

As nouns, mercenary and soldier of fortune are synonyms defined as:

mercenary and soldier of fortune: a person hired to fight for another country than their own

mercenary (noun)	soldier of fortune (noun)
a person hired to fight for another country than their own	a person hired to fight for another country than their own

mercenary (adjective)	soldier of fortune (adjective)
profit oriented
serving for wages in a foreign army
marked by materialism