Zoku(族) is a Sino-Japanese term meaning tribe, clan, or family. As a suffix it has been used extensively within Japan to define subcultural phenomena, though many zoku do not acquire the suffix (e.g. cosplay).

A zoku may be labeled with a Japanese stem (e.g. kaminari zoku) or a foreign language (gairaigo) stem (e.g. saike zoku, where saike comes from "psychedelic").