bales forming the edge of the sumo ring
Sumo term. Refers to the straw bales that form the inner edge of the dohyō (sumo ring).
力士が内俵に足をかけて残った。
The wrestler kept his foot on the inner bales and stayed in the ring.
Compound of 内 (uchi, 'inside') and 俵 (tawara, 'straw bale'), referring to the bales that form the inner boundary of the sumo ring.