Etymology

Obscure, possibly dialect or related to the name of the long-forgotten inventor, or possibly from French couvert ‎(“covered”), although couvert is not used in this sense and the introduction of an l to the English word is difficult to explain.

Another explanation is that the term derives from Tamil கல்வெட்டு ‎(kalveṭṭu, “inscription”) (கல் ‎(kal, “stone”) + வெட்டு ‎(veṭṭu, “cut”) cut stone), a Tamil term for a carved stone bridge allowing passage of a stream below. The term is surmised to have entered into the English lexicon along with anicut from Annaikattu as in Kallanai (Kal - Stone, Anai - Barrier) also known as the Grand Anicut of Tanjore. In the early 1800s Captain Caldwell studied and remodeled the ancient water diversion and regulation systems in the Kaveri river delta, originally built in the 2nd century by Karikala Chola. Culvert, along with Anicut from anaikattu, catamaran from kattumaram, Coleroon from Kollidam, etc., were absorbed into colonial English parlance during that time.

Yet another explanation is that the term derives from an unrecorded Dutch word, possibly coul-vaart, equivalent to coul- (from French, compare couler ‎(“to flow”)) + vaart ‎(“a trip by boat, a canal”) (See fare).