Brit an undergarment that covers the crotch and hips and that may extend to the waist and partly down each leg; underpants
NAmer trousers
bore/scare the pants off somebody
informal to bore/scare somebody very much
by the seat of one's pants
informal by instinct and experience rather than by logic or using mechanical aids
catch somebody with their pants down
informal to take somebody by surprise and at a disadvantage
[short for pantaloons]