I'm of the opinion that if a dictionary is designed to be a reference book rather than a text book - and I assume that this is the case - then any word (or meaning of a word) which gains more than a very local or regional currency, even for a short time, should be included. Think how many archaic or "obsolete" words and definitions of words which are vaguely attributed at best or are a pure and simple guess at worst - ?1320, for instance - simply because no one went to the trouble of defining how the word was used at the time. Do we want future generations to be put in the same position simply to somehow keep dictionaries "pure"? That's horseshit!
And if I'm correct, then all of the words mentioned above should be included in all dictionaries. To hell with the purists. Their continued position in the gene pool seems less than certain, anyway. Too fussy to breed, most of 'em ...
