Hmmm there are quite a few of these… Ok these are UK/us mostly.

America: fanny - backside

UK: fanny - the other side (!)

America: rubber - condom

UK: rubber - something you use to erase pencil marks.

UK and others: Durex - Condom brand

Others: Durex - sticky tape

US: Suspenders - things for holding trousers up

UK: Suspenders - things for holding stockings up. Used with a suspender belt and with, or without, other underwear…

USA: Pants - leg coverings e.g. blue jeans

Most of the UK: Pants - things you wear under your blue jeans (unless ”going commando”)