five-person group; quintet
General term for any group of five people, such as a team, committee, or musical quintet.
このプロジェクトは五人組で進めている。
We are advancing this project as a five-person group.
彼らは
They formed a five-member band.
five-household mutual-aid unit (Edo period)
Historical term for a neighborhood group of five households responsible for mutual aid, tax collection, and self-protection during the Edo period. Now archaic.
江戸時代の五人組は、年貢の納入や防犯に責任を負った。
The five-household units of the Edo period were responsible for tax payment and crime prevention.
Compound of 五 (go, 'five'), 人 (nin, 'person'), and 組 (gumi, 'group'). The historical sense derives from the Edo-period administrative system.