I'd have thought its euphemistic sense was self evident. I've heard it used in the UK occasionally, though it's certainly an Americanism. The original movie "Airplane" uses it this way too, even going so far as to name the inflatable emergency co-pilot "Rock" just as a set-up to this joke ("you mean - we are going to have to..... Blow Rock!!???"). Other than this rather anecdotal evidence though I can't point to any reference that includes this usage. 11:03, 1 Dec 2003 (UTC)