1610s, "expulsion, action of driving away" (a sense now obsolete), noun of action from propuls-, past-participle stem of Latin propellere "to propel" (see propel). The meaning "act of driving forward; propulsive force" is attested by 1799.
1690s, "stream of water," from French jet "a throw, a cast; a gush, spurt (of water); a shoot (of a plant)," from jeter "to throw, thrust" (from PIE root *ye- "to throw, impel"). Middle English had jet/get "a device, mode, manner, fashion, style" (early 14c.).
Sense of "spout or nozzle for emitting water, gas, fuel, etc." is from 1825. Hence jet propulsion (1855, originally in reference to water) and the noun meaning "airplane driven by jet propulsion" (1944, from jet engine, 1943). The first one in service was the German Messerschmitt Me 262. Jet set first attested 1951, shortly before jet commuter plane flights began. Jet age is attested from 1952. The atmospheric jet stream is from 1947.
1775, "pertaining to construction and use of thrown objects," ultimately from Greek ballein "to throw" (from PIE root *gwele- "to throw, reach"). Of rockets or missiles (ones that are guided while under propulsion, but fall freely), from 1949. Ballistic missile is attested from 1954; they attain extreme heights, hence figurative expression go ballistic (1981) "become irrationally angry."
also paddlewheel, "wheel provided with boards or floats around its circumference, for use in moving water," 1680s, so called by its inventor, but the word was not in common use until 1805 and the rise of the steamboat with a side-mounted paddle-wheel turned by steam power for the propulsion of the vessel, from paddle (n.) + wheel (n.).
1918, so called about the time they became popular as aquarium fish, from the scientific name (Girardinus guppii), which honored R.J.L. Guppy, the British-born Trinidad clergyman who supplied the first specimen (1866) to the British Museum. The family name is from a place in Dorset. Other early popular names for it were rainbow fish and million fish. The class of streamlined U.S. submarines (1948) is an acronym from greater underwater propulsion power + -y.
early 14c., "to exempt, exonerate, release, free (from an obligation)," from Old French deschargier "to unload, discharge" (12c., Modern French décharger), from Late Latin discarricare, from dis- "do the opposite of" (see dis-) + carricare "to load a wagon or cart," from Latin carrus "two-wheeled wagon" (see car).
Meaning "to fulfill, to perform (one's duties, etc.)" is from c. 1400. Sense of "dismiss from office or employment" is from c. 1400. Meaning "to unload, to free from, disburden" is late 14c. Of weapons, "send forth by propulsion," transitive, 1550s; "to fire off," intransitive, 1580s. Of a river, "to empty itself," c. 1600. The electrical sense is first attested 1748. Related: Discharged; discharging.