Asm: তিনিচুকীয়া tinasukiẏā
‘Three-cornered Tank’ [Bengmora] City/District, Assam
From Asm: tini, ‘three’; kōṇa, ‘corner’; and pukhuraī, ‘tank’.
Bengmora was the capital of the Motok kingdom which rebelled against the Ahom kings. It was founded by Mezara a.k.a. Swargadeo Sarbananda Singha.
He ordered a triangular tank to be constructed, which was called the Tinikunia Pukhuri. It is possible they found a dead frog in it [Asm: beng, ‘frog’; and marā, ‘dead’].
In 1884 a station was built near this pond and its name was changed to Tinsukia.
Tinsukia District is an industrial region with tea plantations, oil refineries, timber/plywood processing, open cast mining.and a cosmetics manufacturing plant.
Digbhoi refinery is Asia’s oldest (1901) and its Centenary Museum preserves much of the original machinery. It’s name, it is said, comes from the instructions given to workers when the oil was first extracted: ‘Dig, boy, dig!’
For related place names see Indian Place names and Assam place names.

Digboi Centenary Museum Subhashish Panigrahi