Etymology
Advertisement
backscratcher (n.)

also back-scratcher, "rod or other device for scratching one's own back," 1834; see back (n.) + scratch (v.).

Related entries & more 
Advertisement
dehumidifier (n.)

"device for removing humidity from the air," 1909, agent noun from dehumidify (1908); see de- + humidify.

Related entries & more 
latch (n.)

"device for catching and retaining," especially "a fastening for a door," late 13c., probably from latch (v.).

Related entries & more 
sensor (n.)

"device giving a signal about some physical activity," 1947, from a shortened form of sensory (q.v.) or an agent noun in Latin form from sense (v.).

Related entries & more 
gravimeter (n.)

"instrument for measuring the forces of gravity," 1797, from French gravimètre, from gravité (see gravity) + -mètre "measuring device" (see -meter).

Related entries & more 
Advertisement
gin (n.2)

"machine for separating cotton from seeds," 1796, American English, used earlier of other machineries, especially of war or torture, from Middle English gin "ingenious device, contrivance" (c. 1200), from Old French gin "machine, device, scheme," shortened form of engin (see engine). The verb in this sense is recorded from 1789. Related: Ginned; ginning. Middle English had ginful "ingenious, crafty; guileful, treacherous" (c. 1300).

Related entries & more 
MIDI 

"device for connecting computers and electronic musical instruments," 1983, acronym for Musical Instrument Digital Interface.

Related entries & more 
flywheel (n.)

also fly-wheel, "heavy-rimmed revolving wheel to regulate motion," 1784, from fly (n.) "speed-regulating device" (1590s, from fly (v.1)) + wheel (n.).

Related entries & more 
switchboard (n.)

also switch-board, "device for making interchangeable connections between many circuits," 1867, from switch (n.) + board (n.1).

Related entries & more 
sand-trap (n.)

1838, in hydraulics, "device for filtering impurities from water," from sand (n.) + trap (n.). As "golf bunker," by 1906.

Related entries & more 

Page 6