Thanks, Rod - I had an intuition that the "trousers" bit had sexual implications - much London slang does have!

And "scouse" AnnaS - correctly identified as Liverpudlian by m'learned friend - is the name of an old local dish, which was a form of stew containing large anounts of potato and minute amounts of meat (the latter was optional in times of extreme poverty) which was ubiquitous in Liverpool in the late C18 and throughout the C19. The name comes from the Scandinavian, "scause" which means (more or less) "stew."