Alternative spelling of お握り: a grip, a grasp (children's word); a rice ball (vaguely similar to a sandwich)

grip

grip; hold

to grasp, to grip, to hold / to seize, to take hold of / to make (nigirizushi, riceball, etc...); to press into shape

a handful

(idiomatic) to hold the key (to)

(idiomatic) to have something on (someone)

tight / reliable

stable, fulfilled

be fast, securely in place / be reliable, level-headed / keep going, keep trying