While I was out and about I was surprised to see the word humongous on an advertising poster. I always thought it was one of those made up words. It also reminded me of an admonishment from one of my school English teachers about the word ginormous. I decided to settle this once and for all. Off to the OED.
First up: humongous. I'd always thought it ought to be "humungous" with a second "u" (I didn't think people knew the u-sounding o thing any more). Turns out the former is the original US slang. And the word only dates to 1970.
Ginormous is also in there, naturally given as the contraction of gigantic and enormous. The surprise is that it is dated back to 1948. Modern slang in the big scheme of things but quite a lot older than I might have expected. And older than humongous. Score one against the English teachers.
Even more interesting to me, however, was looking at the etymology of humongous - of uncertain origin but influenced by hugeous. Hugeous? A word but a hyperlink away. Given as equivalent to huge, dating back to 1529. Still current (i.e. not listed as obsolete) and I think worth a revival.
As a by the way, meaning in all cases is as expected: "extremely large, excessive in size". Ginormous also has the extra: especially in comparison with one's expectations.