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 "to carry," also "to bear children."

It forms all or part of: Aberdeen; amphora; anaphora; aquifer; auriferous; bairn; barrow (n.1) "frame for carrying a load;" bear (v.); bearing; Berenice; bier; birth; bring; burden (n.1) "a load;" carboniferous; Christopher; chromatophore; circumference; confer; conference; conifer; cumber; cumbersome; defer (v.2) "yield;" differ; difference; differentiate; efferent; esophagus; euphoria; ferret; fertile; Foraminifera; forbear (v.); fossiliferous; furtive; indifferent; infer; Inverness; Lucifer; metaphor; odoriferous; offer; opprobrium; overbear; paraphernalia; periphery; pestiferous; pheromone; phoresy; phosphorus; Porifera; prefer; proffer; proliferation; pyrophoric; refer; reference; semaphore; somniferous; splendiferous; suffer; transfer; vociferate; vociferous.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit bharati "he carries, brings," bhrtih "a bringing, maintenance;" Avestan baraiti "carries;" Old Persian barantiy "they carry;" Armenian berem "I carry;" Greek pherein "to carry," pherne "dowry;" Latin ferre "to bear, carry," fors (genitive fortis) "chance, luck," perhaps fur "a thief;" Old Irish beru/berim "I catch, I bring forth," beirid "to carry;" Old Welsh beryt "to flow;" Gothic bairan "to carry;" Old English and Old High German beran, Old Norse bera "barrow;" Old Church Slavonic birati "to take;" Russian brat' "to take," bremya "a burden," beremennaya "pregnant."

"to delay, put off, postpone," late 14c., differren, deferren, from Old French diferer (14c.) and directly from Latin differre "carry apart, scatter, disperse;" also "be different, differ;" also "defer, put off, postpone," from assimilated form of dis- "away from" (see dis-) + ferre "to bear, carry," from PIE root *bher- (1) "to carry." Etymologically identical with differ; their spelling and pronunciation were differentiated from 15c., perhaps partly by association of this word with delay. Related: Deferred; deferring. 

late 14c., "unbiased, impartial, not preferring one to the other" (of persons), "alike, equal" (of things), from Old French indifferent "impartial" or directly from Latin indifferentem (nominative indifferens) "not differing, not particular, of no consequence, neither good nor evil," from in- "not, opposite of" (see in- (1)) + differens, present participle of differre "set apart" (see differ). Extended sense of "apathetic, no more inclined to one thing than to another" first recorded early 15c.; that of "neither good nor bad" is from 1530s, on notion of "neither more nor less advantageous," but since 17c. it has tended toward "rather bad."