bare-knuckle vs rough-and-tumble

bare-knuckle is not a noun while rough-and-tumble is a noun.

Word	Noun	Adjective	Verb	Adverb
bare-knuckle	No	Yes	No	No
rough-and-tumble	Yes	Yes	No	No

As adjectives, bare-knuckle and rough-and-tumble are synonyms defined as:

bare-knuckle and rough-and-tumble: characterized by disorderly action and disregard for rules

Other synonyms of bare-knuckle include bare-knuckled.

bare-knuckle (noun)	rough-and-tumble (noun)
	disorderly fighting

bare-knuckle (adjective)	rough-and-tumble (adjective)
characterized by disorderly action and disregard for rules	characterized by disorderly action and disregard for rules