also: ばんしゅ
noun
Historical term for a guard serving a daimyo, the emperor, or a similar high-ranking figure in pre-modern Japan.
江戸時代、番衆は大名の屋敷を警護した。
In the Edo period, guards protected the daimyo's residence.
番衆の役目は、夜間の見回りも含まれていた。
The duties of the guards included night patrols as well.
Compound of 番 (ban, 'watch, guard') and 衆 (shū, 'group, people'). The exact historical derivation is uncertain, but the term straightforwardly describes a group of guards.