A unit of measurement of martial prowess. A single corbett being the equivalent of one 'Ronnie Corbett' (OBE and diminutive comedian) defeated in unarmed combat to the death. Subsequent corbetts are presumed to be attacking in concert. ie if a man was rated six corbetts, he would be able to defeat six Ronnie Corbetts simultaneously.
Don't mess with that guy, he'll fucking destroy you, he must be about fify corbetts.
Check out that guy, what a chump, he's barely half a fucking corbett!