From WordNet (r) 3.0 (2006) [wn]:
tank
n 1: an enclosed armored military vehicle; has a cannon and
moves on caterpillar treads [syn: tank, army tank,
armored combat vehicle, armoured combat vehicle]
2: a large (usually metallic) vessel for holding gases or
liquids [syn: tank, storage tank]
3: as much as a tank will hold [syn: tank, tankful]
4: a freight car that transports liquids or gases in bulk [syn:
tank car, tank]
5: a cell for violent prisoners [syn: cooler, tank]
v 1: store in a tank by causing (something) to flow into it
2: consume excessive amounts of alcohol
3: treat in a tank; "tank animal refuse"
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Tank \Tank\ (t[a^][ng]k), n.
A small Indian dry measure, averaging 240 grains in weight;
also, a Bombay weight of 72 grains, for pearls. --Simmonds.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Tank \Tank\ (t[a^][ng]k), n. [Pg. tanque, L. stangum a pool; or
perhaps of East Indian origin. Cf. Stank, n.]
1. A large basin or cistern; an artificial receptacle for
liquids.
[1913 Webster]
2. A pond, pool, or small lake, natural or artificial.
[Webster 1913 Suppl.]
We stood in the afterglow on the bank of the tank
and saw the ducks come home. --F.
Remington.
The tanks are full and the grass is high. --Lawson.
[Webster 1913 Suppl.]
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.
[PJC]
4. a jail cell for temporarily holding prisoners, as in a
police station.
[PJC]
Tank engine, a locomotive which carries the water and fuel
it requires, thus dispensing with a tender.
Tank iron, plate iron thinner than boiler plate, and
thicker than sheet iron or stovepipe iron.
Tank worm (Zool.), a small nematoid worm found in the water
tanks of India, supposed by some to be the young of the
Guinea worm.
[1913 Webster]