Le pantalon

un pantalon = pants/trousers

E.g.
mon pantalon est sale = my pants are dirty

And a very loosely-related word, not widely used but one that always score extra points in a conversation:
une pantalonnade = slapstick comedy, inspired by the character of Pantalone in the commedia dell'arte
Une pantalonnade is used to designate an outrageous buffoonery
Quelle pantalonnade! = what a buffoonery!