lone wolf vs loner

lone wolf and loner both are nouns.

Word	Noun	Adjective	Verb	Adverb
lone wolf	Yes	No	No	No
loner	Yes	No	No	No

As nouns, lone wolf and loner are synonyms defined as:

lone wolf and loner: a person who avoids the company or assistance of others

Other synonyms of lone wolf include lone hand.

lone wolf (noun)	loner (noun)
a person who avoids the company or assistance of others	a person who avoids the company or assistance of others