out-and-out vs downright

out-and-out and downright both are adjectives.

Word	Noun	Adjective	Verb	Adverb
out-and-out	No	Yes	No	No
downright	No	Yes	No	Yes

As adjectives, out-and-out and downright are synonyms defined as:

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

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

out-and-out (adjective)	downright (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

out-and-out (adverb)	downright (adverb)
	thoroughgoing