flanker back vs flanker

flanker back and flanker both are nouns.

Word	Noun	Adjective	Verb	Adverb
flanker back	Yes	No	No	No
flanker	Yes	No	No	No

As nouns, flanker back and flanker are synonyms defined as:

flanker back and flanker: a back stationed wide of the scrimmage line; used as a pass receiver

flanker back (noun)	flanker (noun)
a back stationed wide of the scrimmage line; used as a pass receiver	a soldier who is a member of a detachment assigned to guard the flanks of a military formation
	a back stationed wide of the scrimmage line; used as a pass receiver