downright vs right-down

downright and right-down both are adjectives.

Word	Noun	Adjective	Verb	Adverb
downright	No	Yes	No	Yes
right-down	No	Yes	No	Yes

As adjectives, downright and right-down are synonyms defined as:

downright and right-down: complete and without restriction or qualification; sometimes used informally as intensifiers

Other synonyms of downright include absolute, out-and-out, rank, sheer.

downright (adjective)	right-down (adjective)
complete and without restriction or qualification; sometimes used informally as intensifiers	complete and without restriction or qualification; sometimes used informally as intensifiers
characterized by plain blunt honesty

downright (adverb)	right-down (adverb)
thoroughgoing	positively