v. 25B6; verb
officials began impounding documents : CONFISCATE, appropriate, take possession of, seize, commandeer, expropriate, requisition, sequester, sequestrate; Law distrain.
the cattle were impounded : PEN IN, shut up/in, fence in, enclose, confine; N. Amer. corral.
unfortunates impounded in prison : LOCK UP, incarcerate, imprison, confine, intern, immure, hold captive, hold prisoner.