tanque

The journey of 'tank' begins in South Asia. The Sanskrit and Gujarati word tānkī (or in related forms across Indian languages) meant a cistern, a reservoir, an enclosed body of water — specifically an artificial pool or container built to hold water in a dry climate. Portuguese traders arriving in western India in the 16th century encountered these water tanks across Gujarat and the Deccan, and adopted the word as tanque — which also aligned conveniently with their own existing word tanque, meaning a pool or reservoir, from the Latin stagnum. The convergence of a Portuguese word and an Indian word that sounded similar and meant similar things accelerated the adoption. Tanque passed into English in India as 'tank,' and by the 17th century the English in India used 'tank' for any large water reservoir, natural or artificial.

The armored fighting vehicle was developed by the British military in 1915 and 1916, during the First World War, as a response to the stalemate of trench warfare. The machine — a tracked vehicle carrying guns, able to cross trenches and barbed wire — needed a code name during development and transport to prevent German intelligence from learning what it was. The men in the development program, working under the Landships Committee, chose 'tank' as the cover story: the steel hulls being transported on railway flatcars could plausibly be described as large water-storage containers — tanks — destined for Mesopotamia. The cover name stuck. When the tanks were deployed at the Battle of Flers-Courcelette in September 1916, the secrecy had been maintained long enough that the machines came as a surprise.

The specific person responsible for choosing 'tank' as the code name was Ernest Swinton, one of the primary advocates for the new weapon, though the decision involved several officers. The name had to be plausible for a large metal container. 'Cistern' and 'reservoir' were considered; 'tank' was chosen for its brevity and plausibility. The vehicles were marked 'Tank' on their shipping labels. When military censorship lifted and news reports described the new weapon in action, they used the same word that had been on the shipping documents. The army's code name became the permanent name, in every language, for the weapon category.

The word 'tank' for armored fighting vehicles spread immediately from English into French (char was already in use in French, but tank was adopted as well), German (Panzer was preferred, but tank appeared), Russian, Chinese, Japanese, and virtually every language on earth. It is one of the few English words that has been borrowed unchanged across such a wide range of unrelated language families. The Indian water reservoir, filtered through Portuguese, given a cover story by British military necessity, became one of the most globally recognizable words in any language — and it is now almost impossible for an English speaker to hear 'tank' without thinking of the armored vehicle rather than the water container that gave it its accidental name.