(computing) a hotkey

to use / to employ / to make use of, to apply / to spend

efficiency

(onomatopoeia) ook ook (the sound a monkey makes)

hot

rise, ascend, go up / go in, enter (a house) / get out (of a pool, etc.) / visit, call (on someone) / be promoted, go up (in social standing) / let up, come to an end / flare up (as in fire)

上がる: rise, go up / 挙がる: be cited / 揚がる: be fried / 和了る: (mahjong) to win

work

work; operation

key (to open a lock) / the clue to a problem / key (on the keyboard of a piano etc.) / key (on the keyboard of a computer) / key (a pitch in music)