S: (n) screw (a simple machine of the inclined-plane type consisting of a spirally threaded cylindrical rod that engages with a similarly threaded hole)
S: (n) screw, screw propeller (a propeller with several angled blades that rotates to push against water or air)
S: (n) screw (a fastener with a tapered threaded shank and a slotted head)
S: (n) process, physical process (a sustained phenomenon or one marked by gradual changes through a series of states) "events now in process"; "the process of calcification begins later for boys than for girls"