black suit; mourning clothes
Refers to black clothing, especially formal black suits worn at funerals or in mourning contexts.
It is common to wear a black suit to a funeral.
black-suited staff member
Refers to staff members who wear black suits, typically in restaurants, bars, or adult-entertainment establishments. Often implies a bouncer, waiter, or attendant in such venues.
A man in a black suit was standing at the entrance of the club.
Compound of 黒 (black) and 服 (clothing). The second sense is a metonymic extension from the black suits typically worn by staff in certain service industries.