noun
tekka maki; tuna roll
A type of sushi roll: vinegared rice and sliced raw tuna wrapped in nori seaweed.
回転寿司で鉄火巻を三皿食べた。
I ate three plates of tekka maki at the conveyor-belt sushi restaurant.
The name 鉄火 (tekka, literally 'iron fire') is said to come from the red color of the tuna resembling hot iron, or from the gambling dens (鉄火場) where it was a popular quick snack.