Blether is an alternative form of blather. As nouns the difference between blether and blather is that blether is (blather) while blather is (pejorative) nonsensical or foolish talk. As verbs the difference between blether and blather is that blether is (blather) while blather is (pejorative) to talk rapidly without making much sense.

The verb blither is a variant of blather, meaning to talk nonsensically. Aside from the a / i distinction, the words are the same except for slight connotative differences. Both usually appear in their present-participial forms, blathering and blithering. Blather is preferred by a wide margin in all varieties of English, although blithering is more often used in the phrase blithering idiot.