A blithering idiot is someone so
devoid of intelligence and
wit that they
run around screaming their
inane little thoughts until you
just can't take it anymore and must do away with them.
These people are everywhere: they're the idiots who rule the world and the village idiot.
When saying the words "blithering idiots" you should endeavor to sound as much like John Cleese as you can and as little like Johnny Cash.
Please also see: blundering idiot, complete idiot, idiot convention, moron, simpleton, fool, ass, chowderhead, imbecile, nincompoop, sop, dullard, oaf, dunderhead, noodlehead, numbskull, halfwit.
fortuna favet fatuis!