In this sense the Scots word blether, pronounced to rhyme with tether, means a chat, often a long chat with a good deal of juicy gossip thrown in. For example you might say that many people who join a book group do so to have a good blether over a glass or two of wine rather than to take part in a great literary debate.
When applied to a person the noun blether means someone who is given to talking at too great length. You know the sort. They go wittering on and on long after the listener has ceased to listen. Blether can also be used to refer to someone who is apt to talk a lot of foolish nonsense. Often the two meanings meet together in one person.
The plural form of the noun, blethers, also takes up these themes of foolishness and long-windedness. It means foolish, nonsensical talk or long-drawn-out rambling in which there can be an element of bragging. Bletheration and bletherie are less well-known words for foolish talk
As an exclamation blethers! means nonsense or rubbish. Should someone say something that you are deeply sceptical of or totally in disagreement with you can give expression to your reaction by exclaiming ‘Blethers! If you feel that a stronger expletive is inappropriate.
As with a great many words, the noun blether has a corresponding verb. This was first recorded in Scots in the fifteenth century. Until the nineteenth century it was commonly used to mean to speak indistinctly or to stammer. More usually, its meaning is line with the noun senses of blether and means to talk or chat, to indulge in foolish talk, or to go and on about something, often something unimportant. As is the case with the noun, the verb is also sometimes connected with boasting.
From the verb blether comes bletherin, used both as a noun and adjective to refer to foolish talk or verbosity, and, sometimes, to indistinct speech. Foolish talk and indistinct speech come together in one of the many Scots expressions for to be drunk. The phrase be bletherin fou (=literally, full) means to be so drunk as to talk non-stop nonsense indistinctly. You must have witnessed an example of this, although I am sure that you yourself have never been in such a state.
Blether has an equivalent in English, the word blather, mostly found in informal or dialects contexts. As a verb this means to talk at length either without making much sense or about things that are of little importance. As a noun it means long-winded talk of little meaning or importance.
Blether and blather are Old Norse in origin. They are connected with the Old Norse word blathra meaning nonsense or to speak indistinctly or inarticulately. An alternative form of blather is blither, most commonly found as blithering, as in a blithering idiot.
Blether has brought to us a word which, to me, is rather unattractive, but then it has rather an unattractive meaning. The word is bletherskite, with the alternative forms bletherinskite, bletheranskite and bletherumskite, and it is an insulting term used to refer to a person who talks a lot of nonsense.
The origin of the skite element is uncertain, although it has been suggested that this is derived from skate the fish. Apparently skate was once used as an insult and, certainly we still have the non-flattering term cheapskate.
We passed on the expression bletherskite, in the form blatherskite, not only to some English dialects but also to American English. I will not apologize for this when you think of some of the words that America has passed on to us.