noun
oblong brazier
A traditional Japanese heating device, a long rectangular charcoal brazier often built into the floor or used as a low table, common in older homes and inns.
旅館の部屋には長火鉢が置いてあった。
There was an oblong brazier in the room at the inn.
A kotatsu is a low table with a heater underneath and a quilt over it; a 長火鉢 is an open charcoal brazier, sometimes built into a similar table-like structure but without the quilt.
Compound of 長 (naga, 'long') + 火鉢 (hibachi, 'brazier'), referring to its elongated shape.