We all know at least one of these, I think. Blatherskite is a charming word to describe a person who talks excessively but says little that makes sense. It can also be used as a mass noun to describe nonsense or talk without substance.
Examples of use:
That blatherskites in the café were annoying, yet somewhat entertaining.
Every time I post something, one of those trolling blatherskites chimes in.
He keeps trying to impress people, but he is just full of blatherskite.
Politicians have a tendency towards obfuscating blatherskite.
Etymology: Mid 17th century. From Scottish ‘blather’ (to talk excessively without sense) + ‘skate’ (denoting a person regarded with contempt).