Proto-Indo-European root meaning "under," also "up from under," hence "over."
It forms all or part of: above; assume; Aufklarung; eave; eavesdropper; hyphen; hypo-; hypochondria; hypocrisy; hypotenuse; hypothalamus; hypothesis; hypsi-; hypso-; opal; open; oft; often; resuscitate; somber; souffle; source; soutane; souvenir; sub-; subject; sublime; subpoena; substance; subterfuge; subtle; suburb; succeed; succinct; succor; succubus; succumb; sudden; suffer; sufficient; suffix; suffrage; suggestion; summon; supine; supple; supply; support; suppose; surge; suspect; suspend; sustain; up; up-; Upanishad; uproar; valet; varlet; vassal.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit upa "near, under, up to, on," Greek hypo "under," Latin sub "under, below," Gothic iup, Old Norse, Old English upp "up, upward," Hittite up-zi "rises."
1520s, "footman, running footman, valet," from French laquais "foot soldier, footman, servant" (15c.), a word of unknown origin; perhaps from Old Provençal lacai, from lecai "glutton, covetous," from lecar "to lick." The alternative etymology is that it comes via Old French laquay, from Catalan alacay, from Arabic al-qadi "the judge." Yet another guess traces it through Spanish lacayo, from Italian lacchè, from Modern Greek oulakes, from Turkish ulak "runner, courier." This suits the original sense better, but OED says Italian lacchè is from French. Sense of "servile follower" appeared 1580s. As a political term of abuse it dates from 1939 in communist jargon.
Specific sense of "military servant" is attested from late 13c.; that of "officer whose duty is to enforce judgments of a tribunal or legislative body" is from c. 1300 (sergeant at arms is attested from late 14c.). Meaning "non-commissioned military officer" first recorded 1540s. Originally a much more important rank than presently. As a police rank, in Great Britain from 1839.
Middle English alternative spelling serjeant (from Old French) was retained in Britain in special use as title of a superior order of barristers (c. 1300, from legal Latin serviens ad legem, "one who serves (the king) in matters of law"), from which Common Law judges were chosen; also used of certain other officers of the royal household. sergeant-major is from 1570s. The sergeant-fish (1871) so-called for lateral markings resembling a sergeant's stripes. Related: Sergeancy.
c. 1300, "man consecrated to service in the Christian Church, an ecclesiastic;" also "an agent acting for a superior, one who acts upon the authority of another," from Old French menistre "servant, valet, member of a household staff, administrator, musician, minstrel" (12c.) and directly from Latin minister (genitive ministri) "inferior, servant, priest's assistant" (in Medieval Latin, "priest"), from minus, minor "less," hence "subordinate" (from PIE root *mei- (2) "small") + comparative suffix *-teros. Formed on the model of magister (see master (n.)).
Minister views a man as serving a church; pastor views him as caring for a church as a shepherd cares for sheep; clergyman views him as belonging to a certain class; divine is properly one learned in theology, a theologian; parson, formerly a respectful designation, is now little better than a jocular name for a clergyman; priest regards a man as appointed to offer sacrifice. [Century Dictionary, 1895]
The political sense of "high officer of the state, person appointed by a sovereign or chief magistrate of a country as the responsible head of a department of the government" is attested from 1620s, from notion of "one who renders official service service to the crown." From 1709 as "a diplomatic representative of a country abroad." A minister without portfolio (1841, in a French context) has cabinet status but is not in charge of a specific department.
late Old English cnafa "boy, male child; male servant," from Proto-Germanic *knabon- (source also of Old High German knabo "boy, youth, servant," German knabe "boy, lad"); it is also probably related to Old English cnapa "boy, youth, servant," Old Norse knapi "servant boy," Dutch knaap "a youth, servant," Middle High German knappe "a young squire," German Knappe "squire, shield-bearer." Original sense unknown; Klein suggests the prehistoric meaning might have been "stick, piece of wood." For pronunciation, see kn-.
Sense of "rogue, rascal" is first recorded c. 1200, presumably via sense evolution from "a menial" to "one of low birth," and the low character supposed to be characteristic of such a condition. But through Middle English it kept also its non-pejorative meaning, as in knave-child (Scottish knave-bairn) "male child." In playing cards, "the lowest court card," 1560s.
Previously, the English equivalent of the French valet was normally known as Knave, in the sense of 'serving-lad'. In the seventeenth century it came to be called Jack, from the name properly applied to the Knave of trumps at All Fours. All Fours being a low-class game, the use of 'Jack' for 'Knave' was long considered vulgar. ('He calls the Knaves Jacks!', remarks Estella contemptuously in Dickens's Great Expectations.) When indices came in, it was obviously preferable to use 'J' rather than 'Kn' to avoid confusion with 'K' for King. Jack has since become the normal title of the lowest court, though 'Knave' can still be heard. [David Parlett, "A History of Card Games," 1991]