Green’s Dictionary of Slang

a general pej. description of a person; occas. of a place (see cit. 1960).

1937		R. Westerby Wide Boys Never Work (1938) 109: This chap was a right cowson.
1938		J. Curtis They Drive by Night 175: I got a good mind to finish you off, you yellow cowson.
1947		J. Maclaren-Ross Of Love And Hunger 138: Don’t be took in by him. He’s a right cowson.
1953		J. Franklyn Cockney 286: Bill’s getting his cards this week – shame – some dirty cowson must have been putting the acid in!
1953		R. Mais Hills were Joyful Together (1966) 37: The little monkey, the ugly little cow-son.
1956		J. Curtis Look Long Upon a Monkey 66: Ain’t a bigger cowson wandering about untopped.
1960		J.R. Ackerley We Think The World Of You (1971) 121: You get thinking in a cowson of a place like this.
1966		J. Orton Erpingham Camp (1967) Scene viii: Apologise, you cowson!
1970		B. Naughton Alfie Darling 191: A bleeding great ugly big Rolls comes drawing up alongside. In it was one fat, over-fed cowson.