late 13c., "make deliberate physical contact with," from Old French tochier "to touch, hit, knock; mention, deal with" (11c., Modern French toucher), from Vulgar Latin *toccare "to knock, strike" as a bell (source also of Spanish tocar, Italian toccare), perhaps of imitative origin. Related: Touched; touching.
From c. 1300 in the transitive sense "bring into physical contact," also "pertain to." Other senses attested from 14c. are "perceive by physical contact, examine by sense of touch," also "be or come into physical contact with; come to rest on; border on, be contiguous with;" also "use the sense of touch," and "mention, describe." From early 14c. as "affect or move mentally or emotionally," with notion of to "touch" the heart or mind. Also from early 14c. as "have sexual contact with." Meaning "to get or borrow money" first recorded 1760.
Touch-and-go (adj.) is recorded from 1812, apparently from the name of a tag-like game, first recorded 1650s (however, despite the coincidence, this in no way suggests an acronym origin for tag). Touch football is first attested 1933. Touch-me-not (1590s) translates Latin noli-me-tangere.
screen n.
mid-14c., screne, "upright piece of furniture providing protection from heat of a fire, drafts, etc.," probably from a shortened (Anglo-French? compare Anglo-Latin screna) variant of Old North French escren, Old French escran "fire-screen, tester of a bed" (early 14c.). This is of uncertain origin, though probably from a Germanic source, perhaps from Middle Dutch scherm "screen, cover, shield," or Frankish *skrank "barrier," from Proto-Germanic *skirmjanan(source also of Old High German skirm, skerm "protection," Old Frisian skirma "protect, defend;" from PIE root *sker- (1) "to cut").
The sense of "anything interposed to conceal from view" is by c. 1600. The meaning "net-wire frame used in windows and doors" is recorded from 1859. Meaning "flat vertical surface for reception of projected images" is from 1810, originally in reference to magic lantern shows; later of movies. Transferred sense of "cinema world collectively" is attested from 1914; hence screen test "filmed test of performing abilities" (1918), etc.
The meaning "small fluorescent display on a TV set" is by 1946, extended to the display on a computer monitor by 1970, hence the monitor itself. The computer screen saver is attested by 1990. The meaning "window of an automobile" is by 1904. As a type of maneuver in sports, by 1934 (U.S. football, screen-pass). Screen printing recorded from 1918. Screen-door is from 1840. Screen-time "time spent watching a computer or television screen" is by 1999.