left-of-center vs left-wing

left-of-center and left-wing both are adjectives.

Word	Noun	Adjective	Verb	Adverb
left-of-center	No	Yes	No	No
left-wing	No	Yes	No	No

As adjectives, left-of-center and left-wing are synonyms defined as:

left-of-center and left-wing: believing in or supporting tenets of the political left

Other synonyms of left-of-center include leftist.

left-of-center (adjective)	left-wing (adjective)
believing in or supporting tenets of the political left	believing in or supporting tenets of the political left