Historical term for a watchman, especially during the Edo period. Often associated with fire watch or neighborhood patrol. The cross-reference 番太 is a synonym.
See also: 番太
In the Edo period, the watchman made rounds at night, calling out warnings against fire.
Compound of 番 (ban, 'watch, guard') and 太郎 (tarō, a common male given name often used generically for a man in a role). The exact historical derivation is uncertain, but it likely originated as a colloquial term for a watchman.