disaster n.

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 "star." Buck and others doubt the old suggestion that it is a borrowing from Akkadian istar "venus." The source of the common Balto-Slavic word for "star" (Lithuanian žvaigždė, Old Church Slavonic zvezda, Polish gwiazda, Russian zvezda) is not explained.

It forms all or part of: aster; asterisk; asterism; asteroid; astral; astro-; astrobiology; astrobleme; astrognosy; astroid; astrolabe; astrolatry; astrology; astromancy; astronaut; astronomy; AstroTurf; constellation; disaster; Estella; Esther; instellation; interstellar; lodestar; star; stardust; starfish; starlet; starlight; starry; stellar; stellate.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit star-; Hittite shittar, Greek aster "star," with derivative astron; Latin stella, Breton sterenn, Welsh seren "star."

1580s, "ill-starred, unlucky," a sense now obsolete, from French désastreux (16c.), which is from désastre (see disaster) or else from Italian desastroso. The modern meaning "calamitous, ruinous, of the nature of a disaster," is from c. 1600. Related: Disastrously; disastrousness.