Thanks, YGirl. I think that's basically right, with one caveat (in two parts).: (a) Words mean what their users agree them to mean--in a broad usage context--, whether or not new usages have yet been imprinted in dictionaries; and (b) words are changing meaning all of the time, mutating... -- as anyone may discover by examining dictionaries of many varied vintages.
I once had a letter to the editor of my local newspaper "corrected" before printing, because a word I used wasn't in their outdated dictionary! The word was "heterosexist". My letter was badly botched! All the opinion page editor would have had to do is to google it, and would have found that it was included in many contemporary dictionaries. <sigh>