slackyoudaoicibaDictYouDict[slack 词源字典]
slack: [OE] In common with Dutch and Swedish slak, slack comes from a prehistoric Germanic *slakaz. This was derived from the same ultimate source that produced Latin laxus ‘loose’ (source of English lax, relax, release, and relish) and languēre ‘languish’ (source of English languish). The plural noun slacks was first used for ‘trousers’ in the early 19th century. (The noun slack ‘small pieces of coal’ [15] is a different word, probably borrowed from Middle Dutch slacke ‘waste produced by smelting metal’.)
=> languish, lax, relax, release, relinquish[slack etymology, slack origin, 英语词源]
blast (n.)youdaoicibaDictYouDict
Old English blæst "blowing, breeze, puff of wind," from Proto-Germanic *bles- (cognates: Old Norse blastr, Old High German blast "a blowing, blast," German blasen, Gothic blesan "to blow"), from PIE *bhle- "to blow," probably a variant of root *bhel- (2) "to blow, inflate, swell" (see bole).

Meaning "explosion" is from 1630s; that of "noisy party, good time" is from 1953, American English slang. Sense of "strong current of air for iron-smelting" (1690s) led to blast furnace and transferred sense in full blast "the extreme" (1839). Blast was the usual word for "a smoke of tobacco" c. 1600.
dross (n.)youdaoicibaDictYouDict
"dirt, dregs," Old English dros "the scum thrown off from metals in smelting," from Proto-Germanic *drohs- (cognates: Middle Dutch droes, Dutch droesem, Middle Low German dros, Old High German truosana, German Drusen "dregs, husks"), from PIE dher- (1) "to make muddy." Meaning "refuse, rubbish" is mid-15c.
fluor (n.)youdaoicibaDictYouDict
1660s, an old chemistry term for "minerals which were readily fusible and useful as fluxes in smelting" [Flood], from Latin fluor, originally meaning "a flowing, flow" (see fluent), said to be from a translation of the German miners' name, flusse. Since 1771 applied to minerals containing fluorine, especially calcium fluoride (fluorspar or fluorite).
galena (n.)youdaoicibaDictYouDict
lead ore, lead sulphide, c. 1600, from Latin galena "mix of silver and lead; dross from smelting lead," of unknown origin. Related: Galenic.
Jew (n.)youdaoicibaDictYouDict
late 12c. (in plural, giwis), from Anglo-French iuw, Old French giu, from Latin Iudaeum (nominative Iudaeus), from Greek Ioudaios, from Aramaic jehudhai (Hebrew y'hudi) "Jew," from Y'hudah "Judah," literally "celebrated," name of Jacob's fourth son and of the tribe descended from him. Replaced Old English Iudeas "the Jews." Originally, "Hebrew of the kingdom of Judah."

Jews' harp "simple mouth harp" is from 1580s, earlier Jews' trump (1540s); the connection with Jewishness is obscure. Jew-baiting first recorded 1853, in reference to German Judenhetze. 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.
slag (n.)youdaoicibaDictYouDict
"refuse from smelting," 1550s, from Middle Low German slagge (German Schlacke) "splinter flying off when metal is struck," related to Old High German slahan "to strike, slay" (see slay (v.)).
smelt (v.)youdaoicibaDictYouDict
mid-15c. (implied in smelter), from Dutch or Low German smelten, from Proto-Germanic *smelt- (cognates: Old High German smelzan, German schmelzen "to melt"), from PIE *smeld-, variant of *mel- "soft." Thus the word is from a variant of the stem of Old English meltan "to melt" (see melt (v.)). Related: Smelted; smelting.
wolfram (n.)youdaoicibaDictYouDict
1757, from German Wolfram, wolform "iron tungstate" (1562), of obscure etymology. It looks like "wolf-cream" (from rahm "cream"), but the second element might be Middle High German ram (German Rahm) "dirty mark, soot;" if so, perhaps "so called in sign of contempt because it was regarded of lesser value than tin and caused a considerable loss of tin during the smelting process in the furnace" [Klein]. Or perhaps the word is originally a personal name, "wolf-raven."
zinc (n.)youdaoicibaDictYouDict
1650s, zinke, from German Zink, perhaps related to Zinke "prong, point;" said to have been used first by Paracelsus (c. 1526) on analogy of the form of its crystals after smelting. Zinke is from Old High German zint "a point, jag," from Proto-Germanic *teng- "tine" (cognates: Old Norse tindr "point, top, summit," Old English tind "prong, spike"), from PIE *denk- "to bite." Spelling with -c- is from 1813, from French influence.
cryoliteyoudaoicibaDictYouDict
"A white or colourless mineral consisting of a fluoride of sodium and aluminium. It is added to bauxite as a flux in aluminium smelting", Early 19th century: from cryo- 'cold, frost' (because the main deposits are found in Greenland) + -lite.