sweet-talk vs blarney

sweet-talk is not a noun while blarney is a noun.

Word	Noun	Adjective	Verb	Adverb
sweet-talk	No	No	Yes	No
blarney	Yes	No	Yes	No

As verbs, sweet-talk and blarney are synonyms defined as:

sweet-talk and blarney: influence or urge by gentle urging, caressing, or flattering

Other synonyms of sweet-talk include cajole, coax, inveigle, palaver, wheedle.

sweet-talk (noun)	blarney (noun)
	flattery designed to gain favor

sweet-talk (verb)	blarney (verb)
influence or urge by gentle urging, caressing, or flattering	influence or urge by gentle urging, caressing, or flattering