word-forming element of Latin origin meaning 1. "lack of, not" (as in dishonest); 2. "opposite of, do the opposite of" (as in disallow); 3. "apart, away" (as in discard), from Old French des- or directly from Latin dis- "apart, asunder, in a different direction, between," figuratively "not, un-," also "exceedingly, utterly." Assimilated as dif- before -f- and to di- before most voiced consonants.

The Latin prefix is from PIE *dis- "apart, asunder" (source also of Old English te-, Old Saxon ti-, Old High German ze-, German zer-). The PIE root is a secondary form of *dwis- and thus is related to Latin bis "twice" (originally *dvis) and to duo, on notion of "two ways, in twain" (hence "apart, asunder").

In classical Latin, dis- paralleled de- and had much the same meaning, but in Late Latin dis- came to be the favored form and this passed into Old French as des-, the form used for compound words formed in Old French, where it increasingly had a privative sense ("not"). In English, many of these words eventually were altered back to dis-, while in French many have been altered back to de-. The usual confusion prevails.

As a living prefix in English, it reverses or negatives what it is affixed to. Sometimes, as in Italian, it is reduced to s- (as in spend, splay, sport, sdain for disdain, and the surnames Spencer and Spence).

Proto-Indo-European root meaning "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule."

It forms all or part of: abrogate; address; adroit; Alaric; alert; anorectic; anorexia; arrogant; arrogate; bishopric; correct; corvee; derecho; derogate; derogatory; Dietrich; direct; dress; eldritch; erect; ergo; Eric; Frederick; Henry; incorrigible; interregnum; interrogate; maharajah; Maratha; prerogative; prorogue; rack (n.1) "frame with bars;" rail (n.1) "horizontal bar passing from one post or support to another;" Raj; rajah; rake (n.1) "toothed tool for drawing or scraping things together;" rake (n.2) "debauchee; idle, dissolute person;" rakish; rank (adj.) "corrupt, loathsome, foul;" real (n.) "small Spanish silver coin;" realm; reck; reckless; reckon; rectangle; rectify; rectilinear; rectitude; recto; recto-; rector; rectum; regal; regent; regicide; regime; regimen; regiment; region; regular; regulate; Regulus; Reich; reign; resurgent; rex; rich; right; Risorgimento; rogation; royal; rule; sord; source; subrogate; subrogation; surge; surrogate; viceroy.

It is the hypothetical source of/evidence for its existence is provided by:

Sanskrit raj- "a king, a leader," rjyati "he stretches himself," riag "torture" (by racking); Avestan razeyeiti "directs," raštva- "directed, arranged, straight;" Persian rahst "right, correct;" Latin regere "to rule, direct, lead, govern," rex (genitive regis) "king," rectus "right, correct;" Greek oregein "to reach, extend;" Old Irish ri, Gaelic righ "a king," Gaulish -rix "a king" (in personal names, such as Vircingetorix), Old Irish rigim "to stretch out;" Gothic reiks "a leader," raihts "straight, right;" Lithuanian raižytis "to stretch oneself;" Old English rice "kingdom," -ric "king," rice "rich, powerful," riht "correct;" Gothic raihts, Old High German recht, Old Swedish reht, Old Norse rettr "correct."

mid-14c., "rule, control," verbal noun from dress (v.). In some Middle English uses also short for addressing. In cookery, "sauce used in preparing a dish for the table," from c. 1500. Meaning "bandage applied to a wound or sore" is by 1713.

Dressing-gown "a loose and easy robe worn while applying makeup or doing the hair" is attested from 1777; dressing-room "room intended to be used for dressing" is from 1670s. Dressing-up "act or fact of attiring oneself with attention to style and fashion" is by 1852. Dressing-down (n.) "a reprimand" is by 1839, American English, originally "a thrashing," perhaps ironic or extended from some 19c. mechanical or commercial sense.

also dress-maker, "one whose occupation is the making of articles of feminine attire," 1803, from dress (n.) + maker.

also headdress, 1703, from head (n.) + dress (n.) in the older, more general, sense.

also sundress, 1942, from sun (n.) + dress (n.).

early 14c., "to guide, aim, or direct," from Old French adrecier "go straight toward; straighten, set right; point, direct" (13c.), from Vulgar Latin *addirectiare "make straight" (source also of Spanish aderezar, Italian addirizzare), from ad "to" (see ad-) + *directiare "make straight," from Latin directus "straight, direct" past participle of dirigere "set straight," from dis- "apart" (see dis-) + regere "to direct, to guide, keep straight" (from PIE root *reg- "move in a straight line"). Compare dress (v.)).

The oldest sense in English is preserved in the terminology of golf (to address a ball). The meaning "direct for transmission, write as a destination on a message" is from mid-15c. The meaning "direct spoken words (to someone)" is from late 15c. From late 14c. as "to set in order, repair, correct." The attempt (falsely) re-Latinize the spelling to add- began in France 15c. but failed there (the Modern French verb is adresser); it stuck in English. Related: Addressed; addressing.

late 14c., directen, "to write or address (a letter, words)" to someone, also "to point or make known a course to," from Latin directus past participle of dirigere "set straight, arrange; give a particular direction to, send in a straight line; guide" a thing, either to something or according to something, from dis- "apart" (see dis-) + regere "to direct, to guide, keep straight" (from PIE root *reg- "move in a straight line"). Compare dress; address.

Sense of "to point or aim in a straight line toward a place or an object" is from c. 1400. Meaning "to govern, regulate as to behavior, prescribe the course or actions of" is from early 15c. Sense of "to order, ordain" is from 1650s. Sense of "to write the destination on the outside of a letter" had emerged by 17c. In reference to plays, films, etc., "to supervise and control the making of," it is attested from 1913. Related: Directed; directing.

"skilled form of horseback riding performed in exhibitions and competitions," 1936, from French dressage, from dresser "to train, drill" (see dress (v.)). Middle English had dress (v.) in the sense of "to train or break in" a horse or other animal (c. 1400), but it died out.

c. 1300, "person who prepares or furnishes (something)," agent noun from dress (v.). Meaning "table, sideboard" (on which food is prepared) is from late 14c., from Old French dresseur, dreçoir "table to prepare food," from dresser "prepare, dress." Sense of "one who is employed in clothing or adorning others" is from 1510s. Meaning "chest, dressing bureau" is by 1895.