blabbermouthed vs talkative

blabbermouthed and talkative both are adjectives.

Word	Noun	Adjective	Verb	Adverb
blabbermouthed	No	Yes	No	No
talkative	No	Yes	No	No

As adjectives, blabbermouthed and talkative are synonyms defined as:

Other synonyms of blabbermouthed include bigmouthed, blabby.

blabbermouthed (adjective)	talkative (adjective)
prone to communicate confidential information	friendly and open and willing to talk
unwisely talking too much	unwisely talking too much
	full of trivial conversation