ETYM Portu. tanque, Latin stangum a pool; or perhaps of East Indian origin. Related to Stank.
1. A large (usually metallic) container for holding gases or liquids; SYN. storage tank.
2. As much as a tank will hold; SYN. tankful.

An enclosed armored military vehicle; has a cannon and moves on caterpillar treads; SYN. army tank, armored combat vehicle.
Armored fighting vehicle that runs on tracks and is fitted with weapons systems capable of defeating other tanks and destroying life and property. The term was originally a code name for the first effective tracked and armored fighting vehicle, invented by the British soldier and scholar Ernest Swinton, and first used in the Battle of the Somme 1916.
A tank consists of a body or hull of thick steel, on which are mounted machine guns and a larger gun. The hull contains the crew (usually consisting of a commander, driver, and one or two soldiers), engine, radio, fuel tanks, and ammunition. The tank travels on caterpillar tracks that enable it to cross rough ground and debris. It is known today as an MBT (main battle tank).
The name arose from the cover used when developing the British prototype. In an endeavor to keep the project secret, the test model was described as a “water carrier for Mesopotamia”, from which it became known in the factory as “that tank thing”. The French, working on a separate project to develop a tank simply, called it char (lit., “automobile”).

1. To store in a tank by causing (something) to flow into it.
2. To treat in a tank