Seems to be an interesting battle going on in that Wikipedia thread! Over most of the UK pants is short for Underpants - which describes the garment worn under ones pantaloons. Trousers derives from from the early Middle English trouse.
Now I have just been all sensible and I am not meant to be doing that this week. So to lower the tone slightly try this. At the next party you are at go up to a crowd of ladies and pull the linings out of your trouser (or pantaloon) pockets - then say to the girls - do you want to see my elephant impression?
