idle talk vs blether

idle talk and blether both are nouns.

Word	Noun	Adjective	Verb	Adverb
idle talk	Yes	No	No	No
blether	Yes	No	Yes	No

As nouns, idle talk and blether are synonyms defined as:

Other synonyms of idle talk include chin music, prate, prattle.

idle talk (noun)	blether (noun)
idle or foolish and irrelevant talk	idle or foolish and irrelevant talk

idle talk (verb)	blether (verb)
	to talk foolishly