A crusty, ill-tempered geezer or scrooge.
"The women should’ve answered back with, “We’d ask you the same thing, but everyone knows the answer to that, you curmudgeon ass coot.” - Dlisted
A walking idiot or lowlife. Leave it to the British to come up with the best insults! "Bus wanker!" 2.) A dude who enjoys yanking his wank. A true master of his own bation.