A container or reservoir for holding liquid or gas, often in compounds such as ガソリンタンク or 貯水タンク.
I put gasoline into the gas tank.
We store water in a tank.
The car's gas tank is almost empty.
After driving for a long time, the tank became empty.
I filled the tank up before departing.
タンク is a loanword for any tank (water, fuel, gas, etc.), whereas 水槽 specifically implies a tank meant to hold water.
タンク is the ordinary modern word for a tank, while 船 in the tank sense is limited to compounds like 湯船 or specialized usage.
stand; base; platform; table; rack · setting (of a gem); mounting · stock (in grafting) · counter for machines and vehicles · level; mark; range; decade (of one's life) · tall building (with a fine view); observation platform · plateau; heights
think tank
tank truck; tanker truck; road tanker
tank car; tank truck
plastic container; poly tank
hot water tank
Written in katakana as a foreign-style word; no language of origin is specified.
tank top
tank bag (motorcycle)
tank breathing