noun
double underarm grip (sumo)
A sumo technique where a wrestler reaches under both of the opponent's arms to grip the back of the mawashi, preventing the opponent from grabbing the belt. Highly advantageous offensive position.
横綱は立ち合いからもろ差しを狙った。
The yokozuna aimed for a double underarm grip from the initial charge.
もろ差しになると相手は攻め手を失った。
Once he got the double underarm grip, his opponent lost any means of attack.
Irregular kanji usage; 諸 normally reads しょ or もろ (as in 諸手) but this spelling is non-standard.
Compound of もろ (both) and 差し (from 差す, to insert/put in). The kanji spellings 両, 双, and 諸 all convey the idea of 'both' or 'together'.