in later sense of "large artificial container for liquid" (1690) by Port. tanque "reservoir," from estancar "hold back a current of water," from V.L. *stanticare (see stanch
). But others say the Port. word is the source of the Indian ones. Meaning "fuel container" is recorded from 1902. Military use originated 1915, partly as a code word, partly because they looked like benzene tanks. They were first used in action at Pozieres ridge, on the Western Front, Sept. 15, 1916. Slang meaning "detention cell" is from 1912.
"to lose or fail," 1976, originally in tennis jargon, but said there to be from boxing, from tank
(n.) in some sense. Tanked "drunk" is from 1893.