anti-Semitism n.

word-forming element of Greek origin meaning "against, opposed to, opposite of, instead," shortened to ant- before vowels and -h-, from Old French anti- and directly from Latin anti-, from Greek anti (prep.) "over, against, opposite; instead, in the place of; as good as; at the price of; for the sake of; compared with; in opposition to; in return; counter-," from PIE *anti "against," also "in front of, before" (from root *ant- "front, forehead," with derivatives meaning "in front of, before"), which became anti- in Italian (hence antipasto) and French.

It is cognate with Sanskrit anti "over, against," and Old English and- (the first element in answer). A common compounding element in Greek, in some combinations it became anth- for euphonic reasons. It appears in some words in Middle English but was not commonly used in English word formations until modern times. In a few English words (anticipate, antique) it represents Latin ante.

In noun compounds where it has the sense of "opposed to, opposite" (Antichrist, anti-communist) the accent remains on the anti-; in adjectives where it retains its old prepositional sense "against, opposed to," the accent remains on the other element (anti-Christian, anti-slavery).

1847, "a Jew, Arab, Assyrian, or Aramaean" (an apparently isolated use from 1797 refers to the Semitic language group), back-formation from Semitic or else from French Sémite (1845), from Modern Latin Semita, from Late Latin Sem, Greek Sēm "Shem," one of the three sons of Noah (Genesis x.21-30), regarded as the ancestor of the Semites in Bible-based anthropology, from Hebrew Shem. In this modern sense it is said to have been introduced by German historian August Schlözer in 1781.

The credit, if such it be, of having originated the name "Semitic" (from Noah's son Sem or Shem) for the Hebrew group, is to be given either to Schlözer or to Eichhorn, — to which of the two is doubtful. The first known use of the term is in Schlözer's article on the Chaldæans, in Eichhorn's Repertorium, 8, 161 (1781), and he seems to claim the honor of its invention ; but a similar claim is made by Eichhorn himself, without mention of Schlözer, in his Allgemeine Bibliothek, 6, 772 (1794). [Philip Schaff, ed., "Religious Encyclopedia," 1889]