1.A large basin or cistern; an artificial receptacle for liquids.
2.A pond, pool, or small lake, natural or artificial. "We stood in the afterglow on the bank of the tank and saw the ducks come home." "The tanks are full and the grass is high."
3.(Mil.) A heavily armored combat vehicle which moves on caterpillar treads, rather than wheels. It typically carries a cannon and a heavy machine, and sometimes other weapons. It is the main distinguishing weapon of an armored division.
4.A jail cell for temporarily holding prisoners, as in a police station.
