For a given definition of "comprehensive", as your example nicely demonstrated (As an aside, your example made me wish I had access to DARE). How comprehensive is a dictionary that includes archaic slang from one part of the English-speaking world but contains little from elsewhere and perforce nothing at all from later times? A simple example, suggested phonetically by your own: The word "kai" is standard in NZE, a loanword from Māori, and means "food". The OED lists its first recorded published use in English as predating the Websters by 85 years, yet searching for the word in Webster's 1913 gives me a 404.

To bring this back to the topic at hand, this is why I don't have a problem with the Kobo's inbuilt dictionary - it's good enough most of the time, and when it's not, Kobo offers the option itself to search Google, which fills in most of the gaps


P.S. - I wonder if the shoplifting sense of "kipe" derives ultimately from the "fishing basket" sense? Not that much of a stretch, I'd say