machine; machinery

complex (not simple or straightforward)

gear

to stir, shake, shift, swing / (as of a machine or device) to operate, run, go, work / (as of a person or group) to work, go into action / (emotionally) to be moved, touched, influenced

to move

(obsolete) to move

器械: a device, an appliance, a mechanism / 機械: a machine, equipment, an apparatus / 器械: a utensil, a tool, an instrument / 器械: a tool for conducting a test or experiment or for measurement

Alternative spelling of 組合せ数学 (“combinatorics”)

(idiomatic) have a craving for, have a strong desire for, itch for

to never go back on one's decision no matter what