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What do you say when someone uses many words, without getting to the point and without saying something really of value with regard to a particular topic? I'd like to emphasize that it's really a lengthy statement with only little content which is actually relevant to what has been asked. It can seem sophisticated, but when you look closely it's either trivial conclusions or doesn't even answer the question.
I've heard the expression "mental masturbation", but maybe there are better ones.
EDIT: It is not merely lengthy or long-winded. It is rather off-topic or not relevant. It can be rather focussed and condensed - just on things which are irrelevant. Often the talker believes he is being very clever by mentioning complicating stuff.