a piece of clothing that covers the body from the waist down and is divided into two parts to cover each leg separately a pair of grey trousers I was still in short trousers (= still only a boy) at the time. He dropped his trousers. See related entries: Clothes Word Origin early 17th cent.: from archaic trouse (singular) from Irish triús and Scottish Gaelic triubhas (see trews), on the pattern of drawers.Extra examples He disapproves of women in trousers. He dropped his trousers in a rude gesture. He quickly pulled on his trousers and a T-shirt. I was still in short trousers at the time. I was still in short trousers= still only a boy at the time.