Eugene Volokh doubts not truth to be a liar, but does doubt a common claim about Shakespeare that always made no sense to me either, but I certainly wasn't going to do any research on the matter.
Well, someone has, and, by my troth, it seemed he was but having a virtue assumed for him while having it not:
Shakespeare is often given credit for coining not just memorable phrases, but also hundreds of now-familiar words……
But the recent scanning of early English books in fully searchable format (see, for instance, Chadwyck-Healey's Early English Books Online [EEBO]) lets us test these claims — and it appears that many of them are mistaken.
Volokh hits the same point that always bothered me about this: it just seems quite unlikely that a popular playwright would fill his plays with words he made up that no one in his audience of sodden-witted lords had ever heard of before.
It is, after all, use that doth breed habit in a man, and language as well. Or whatever. By gum, with such strategems it seemed he'd get about as far as the Stranglers did when inventing the word "Shakespearos."