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c.1300, "to rush, plunge, leap, start forth; to be set into sudden motion," from Old North French lancher (Old French lancier) "to fling, hurl, throw, cast," from Late Latin lanceare "wield a lance," from Latin lancea "light spear" (see lance). Sense of "set (a boat) afloat" first recorded c.1400, from notion of throwing it out on the water; generalized by 1600 to any sort of beginning. The noun meaning "a leap or a bound" is from mid-15c., from the verb. Meaning "the liftoff of a missile, spacecraft, etc." is from 1935. Launch pad attested from 1960.
"large boat carried on a warship," 1690s, from Portuguese lancha "barge, launch," apparently from Malay lancharan, from lanchar "quick, agile;" English spelling influenced by launch (v.).
largest of a ship's boats, at one time sloop-rigged and often armed, such as those used in the Mediterranean Sea during the 18th and 19th centuries. Although present-day launches can travel under sail or by oar, most are power-driven. Because of their weight, they are seldom used by merchant ships but are often deployed as armed craft from warships. Launches are capable of carrying large numbers of men and are also useful for transporting anchors, cannons, and other heavy objects.