I need some pants

What are pants? Well - in America they refer to the items of clothing you put on your legs - but in London these garment of clothings are called trousers.
In London pants are things you wear under clothing - underwear. Confused? Me too.
Lets start again.
Pants = trousers (in America)
Pants = underwear (in London)

A few years ago I was shopping in London with a friend of mine. I came out of the dressing room and I wanted to show her some jeans I had tried on. I said 'Hey, what do u think of these pants?' She went bright red because she thought I was asking her about underwear and she didn't know why I was yelling about underwear half way across the store.

So, a small child who shall remain nameless asked me, well if in America pants are trousers, then what is underwear called. I said just underwear. You wouldn't hear too many Americans say knickers.... lol!!!