Spelling with J- predominated from 16c. Replaced Old English Iudeas "the Jews," which is from Latin. As an offensive and opprobrious term, "person who seeks gain by sordid means," c. 1600. Jews' harp "simple mouth harp" is from 1580s, earlier Jews' trump (1540s); the connection with Jewishness is obscure, unless it is somehow biblical.
In uneducated times, inexplicable ancient artifacts were credited to Jews, based on the biblical chronology of history: such as Jews' money (1570s) "Roman coins found in England." In Greece, after Christianity had erased the memory of classical glory, ruins of pagan temples were called "Jews' castles," and in Cornwall, Jews' houses was the name for the remains of ancient tin-smelting works.
plural of Sephardi "a Spanish or Portuguese Jew," 1851, from Modern Hebrew Sepharaddim "Spaniards, Jews of Spain," from Sepharad, name of a country mentioned only in Obadiah v.20, probably meaning "Asia Minor" or a part of it (Lydia, Phrygia), but identified by the rabbis after the Targum Jonathan as "Spain." As distinct from Ashkenazim (q.v.). Related: Sephardic.
The Aeolian harp (the phrase is attested from 1791) was made of tuned strings set in a frame; passing breezes caused them to sound harmoniously. Another name for it was anemochord (1832). The ancient district of Aiolis in Asia Minor was said to have been named for the wind god, hence Aeolian also refers to one branch of the ancient Greek people.
"religious system revealed by Muhammad," 1816, from Arabic islam, literally "submission" (to the will of God), from root of aslama "he resigned, he surrendered, he submitted," causative conjunction of salima "he was safe," and related to salam "peace."
... Islam is the only major religion, along with Buddhism (if we consider the name of the religion to come from Budd, the Divine Intellect, and not the Buddha), whose name is not related to a person or ethnic group, but to the central idea of the religion. ["The Heart of Islam: Enduring Values for Humanity," Seyyed Hossein Nasr, 2002]
Earlier English names for the faith include Mahometry (late 15c.), Muhammadism (1610s), Islamism (1747), and Ismaelism (c. 1600; see Ismailite). The Ismailites were not numerous in Islam, but among them were the powerful Fatimid dynasty in Egypt and the Assassins, both of which loomed large in European imagination. This use also is in part from Ishmaelite, a name formerly given (especially by Jews) to Arabs, as descendants of Ishmael (q.v.).
Middle English sabat, from Old English sabat "seventh day of the week in the Jewish calendar; Saturday" as observed by the Jews as a day of rest from secular employment and of religious observance, from Old French sabat and directly from Latin sabbatum, from Greek sabbaton, from Hebrew shabbath, properly "day of rest," from shabath "he rested" (from labor). The spelling with -th is attested from late 14c. but was not widespread until 16c.
The Babylonians regarded seventh days as unlucky, and avoided certain activities on them; the Jewish observance might have begun as a similar custom. Among European Christians, the time of "Sabbath" shifted from the seventh day to the first (Sunday) via the Christians' celebration of the Lord's resurrection on the first day of the week (a Christian Sabbath) "though no definite law, either divine or ecclesiastical, directed the change" [Century Dictionary], but elaborate justifications have been made. In English Sabbath as "Sunday" is evident by early 15c. The sense change was completed among the English people generally during the Reformation.
The original use of the word is preserved in Spanish Sabado, Italian Sabato, and other languages' names for "Saturday." Hungarian szombat, Rumanian simbata, French samedi, German Samstag "Saturday" are from Vulgar Latin *sambatum, from Greek *sambaton, a vulgar nasalized variant of sabbaton. Gothic Sabbato, Sabbatus probably are directly from Greek.
The meaning "any day (or month or year) in which religious rest is enjoined" is by late 14c.; the word also was used in Medieval Latin of any feast day, the solstice, etc. Sabbath-breaking "act of profaning the Sabbath" is attested from 1650s (to break the Sabbath is from late 14c.), formerly a legal violation in parts of the old U.S., "immoral, disturbing, or unnecessary labors or practices" [Century Dictionary]. Sabbath-school is by 1798.