Mandem is a young person’s word, especially in Britain, for your male friends — the boys you hang around with, your crew. “Where’s the mandem?” means “Where are the guys?” It is informal, spoken, and in-group; you would not put it in a school essay, and older people generally do not say it. Girls’ groups have had parallel words, though mandem is the one you will hear most. It is one person talking about a bunch of men, not a formal word for “men” in general.

英國年輕人說的「兄弟們、那幫男生」。台灣沒有對應俚語，語感接近「死黨」（限男生）。