"secret, private, hidden, furtive," 1560s, from Latin clandestinus "secret, hidden," from clam "secretly," from adverbial derivative of base of celare "to hide" (from PIE root *kel- (1) "to cover, conceal, save"), perhaps on model of intestinus "internal." Related: Clandestinely. As a noun form, there is awkward clandestinity (clandestineness apparently being a dictionary word).
Proto-Indo-European root meaning "to cover, conceal, save."
It forms all or part of: Anselm; apocalypse; Brussels; caliology; Calypso; calyx; ceiling; cell; cellar; cellular; cellulite; cellulitis; cilia; clandestine; cojones; coleoptera; color; conceal; eucalyptus; hall; hell; helm (n.2) "a helmet;" helmet; hold (n.2) "space in a ship below the lower deck;" hole; hollow; holster; housing (n.2) "ornamental covering;" hull (n.1) "seed covering;" kil-; kleptomania; occult; rathskeller; supercilious; Valhalla; William.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit cala "hut, house, hall;" Greek kalia "hut, nest," kalyptein "to cover," koleon, koleos "sheath," kelyphos "shell, husk;" Latin cella "small room, store room, hut," celare "to hide, conceal," clam "secret," clepere "to steal, listen secretly to;" Old Irish cuile "cellar," celim "hide," Middle Irish cul "defense, shelter;" Gothic hulistr "covering," Old English heolstor "lurking-hole, cave, covering," Gothic huljan "to cover over," hulundi "hole," hilms "helmet," halja "hell," Old English hol "cave," holu "husk, pod;" Old Prussian au-klipts "hidden;" Old Church Slavonic poklopu "cover, wrapping."
mid-14c., "table where a money lender does business," from Old French contouer, comptoir "counting room; table or bench of a merchant or bank" (14c.), from Medieval Latin computatorium "place of accounts," from Latin computatus, past participle of computare "to count, sum up, reckon together" (see compute).
Generalized 19c. from banks to shops, then extended to display cases for goods. In reference to a similar construction in a home kitchen by 1875. Over-the-counter in reference to goods sold and money paid is by 1875; phrase under the counter in reference to illegal or clandestine transactions is by 1926.
early 14c., "a lover or wooer" of either sex, noun use of adverbial phrase par amour (c. 1300) "passionately, with strong love or desire," from Anglo-French and Old French par amour, from accusative of amor "love," from amare "to love" (see Amy). Originally a term for Christ (by women) or the Virgin Mary (by men), it came to mean "darling, sweetheart" (mid-14c.) and "wife, husband," also, in a bad sense, "mistress, concubine; (a woman's) male lover; clandestine lover" (late 14c.) which from 17c. became the only sense, except in poetry.
1610s, "to trick, deceive, cheat," from French intriguer (16c.), from Italian intrigare "to plot, meddle; perplex, puzzle," from Latin intricare "to entangle, perplex, embarrass" (see intricate).
Meaning "to plot or scheme" is recorded by 1714. That of "to excite curiosity" is from 1894 (OED calls this use "A modern gallicism"). It also could mean "carry on a clandestine or illicit sexual relationship" (1650s). The word appears earlier in English as entriken "entangle, ensnare; involve in perplexity, embarrass" (late 14c.), from Old French entrique or directly from the Latin verb. Related: Intrigued; intriguer; intriguing. Dutch intrigueren, German intriguiren are from French.
"illegal and clandestine copying and sharing of literature," 1967, from Russian samizdat, "self-publishing," from sam "self" (from PIE root *sem- (1) "one; as one, together with") + izdatel'stvo "publishing" (from iz "from, out of," from PIE *eghs; see ex-; + dat' "to give," from PIE root *do- "to give"). The formation is said to be a word-play on Gosizdat, the former state publishing house of the USSR. One who took part in it was a samizdatchik (plural samizdatchiki). Later and less common was tamizdat "writings published abroad and smuggled back into the USSR," from tam "there."
in the modern sense, 1944, especially in reference to Jewish tactics against the British in Palestine — earlier it was used of extremist revolutionaries in Russia who attempted to demoralize the government by terror (1866); and Jacobins during the French Revolution (1795) — from French terroriste; see terror + -ist (also see terrorism).
The term now usually refers to a member of a clandestine or expatriate organization aiming to coerce an established government by acts of violence against it or its subjects. [OED]
The tendency of one party's terrorist to be another's guerrilla or freedom fighter was noted in reference to the British action in Cyprus (1956) and the war in Rhodesia (1973). The word terrorist has been applied, at least retroactively, to the Maquis resistance in occupied France in World War II (as in in the "Spectator," Oct. 20, 1979).