blether vs gabble

blether and gabble both are nouns.

Word	Noun	Adjective	Verb	Adverb
blether	Yes	No	Yes	No
gabble	Yes	No	Yes	No

As verbs, gabble is a hypernym of blether; that is, gabble is a word with a broader meaning than blether:

Other hypernyms of blether include blab, blabber, chatter, clack, gibber, maunder, palaver, piffle, prate, prattle, tattle, tittle-tattle, twaddle.

blether (noun)	gabble (noun)
idle or foolish and irrelevant talk	rapid and indistinct speech

blether (verb)	gabble (verb)
to talk foolishly	speak (about unimportant matters) rapidly and incessantly