Colloquial term for sushi, used especially in casual conversation or among sushi chefs. The cross-reference to 寿司 indicates it is a slang or jargon variant.
See also: 寿司
Wanna go grab some sushi tonight?
The sushi at that place has huge toppings.
Sushi-shop jargon derived from the name 弥助, the assumed name of the sushi-shop proprietor 平維盛 in the kabuki and puppet-play tradition of 義経千本桜.