blether vs twaddle

blether and twaddle both are nouns.

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

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

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

blether (noun)	twaddle (noun)
idle or foolish and irrelevant talk	pretentious or silly talk or writing

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