"informal session of folk musicians," 1940, American English, earlier "a gadget" (1927), of unknown origin, perhaps a nonsense word.
Another device used by the professional car thief, and one recently developed to perfection, according to a large Chicago lock-testing laboratory, is a "hootenanny," so-called by the criminals using it. [Popular Mechanics, February 1931]
of medicines, "kept in stock by a druggist," 1660s, from French officinal, from Medieval Latin officinalis, literally "of or belonging in an officina," a storeroom (of a monastery) for medicines and necessaries, in classical Latin "workshop, manufactory, laboratory," contraction of *opificina, from opifex (genitive opificis) "worker, workman, maker, doer" (from opus "work," from PIE root *op- "to work, produce in abundance") + -fex, -ficis "maker, one who does," from facere "to do, make" (from PIE root *dhe- "to set, put"). Related: Officinally.
1935, as visual equivalent of audio, from Latin video "I see," first person singular present indicative of videre "to see" (see vision). As a noun, "that which is displayed on a (television) screen," 1937.
Engineers, however, remember the sad fate of television's first debut and are not willing to allow "video transmission" (as television is now called by moderns) to leave the laboratory until they are sure it will be accepted. [The Michigan Technic, November 1937]
video game is from 1973.