detention prison; remand prison
A prison for holding suspects or defendants awaiting trial, as opposed to a prison for convicted criminals. Used in legal and administrative contexts.
A detention prison is a facility that houses suspects awaiting trial.
刑務所 is a prison for convicted criminals serving a sentence, contrasting with 未決監 which holds pre-trial detainees.
Compound of 未決 (pending decision, undecided) and 監 (prison, jail). The term is a straightforward legal compound referring to a facility for those whose cases have not yet been decided.