litmus "blue dye-stuff obtained from certain lichens," early 14c., from M.Du. lijkmoes (Du. lakmoes), from lac (see LAC (Cf. lac)) + moes "pulp." Another theory is that it represents O.N. litmose, lit. "lichen for dying," from O.N. lita "to dye, to stain," from litr "color, dye" (see LIT (Cf. lit) (n.1)) + mos "moss." Yet another idea connects the first element to M.Du. leken "to drip, leak" (see LEAK (Cf. leak) (v.)). Whichever was the original word, it probably was influenced by the others. The dye is obtained from certain lichens. It is naturally blue but turns red in acid and is restored to blue by alkalis. Figurative use of litmus test is first attested 1957, from scientific use of litmus-treated paper as a chemical indicator. Litmus paper with this meaning is from 1803.

Etymology dictionary. 2014.

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  • Litmus — or litmus test may refer to:* Litmus test (chemistry), a common pH test * Litmus (Mozilla), a test case management tool maintained by Mozilla * Litmus (Battlestar Galactica), an episode in the first season of the Battlestar Galactica television… …   Wikipedia

  • Litmus — Lit mus, n. [D. lakmoes; lak lacker + moes a thick preparation of fruit, pap, prob. akin to E. meat: cf. G. lackmus. See {Lac} a resinous substance.] (Chem.) A dyestuff extracted from certain lichens ({Roccella tinctoria}, {Lecanora tartarea},… …   The Collaborative International Dictionary of English

  • litmus — m. Sustancia extraída de ciertos líquenes, con la que se prepara la tintura de *tornasol a la que comunica la cualidad de volverse roja por la acción de los ácidos …   Enciclopedia Universal

  • litmus — ► NOUN ▪ a dye obtained from certain lichens that is red under acid conditions and blue under alkaline conditions. ORIGIN from Old Norse words meaning dye and moss …   English terms dictionary

  • litmus — [lit′məs] n. [ON litmose, lichen used in dyeing < litr, color (akin to Goth wlits, face < IE * witu , appearance < base * wel , to see > L voltus, expression, Welsh gweled, to see) + mosi, MOSS] a purple coloring matter obtained from… …   English World dictionary

  • litmus — /lit meuhs/, n. a blue coloring matter obtained from certain lichens, esp. Roccella tinctoria. In alkaline solution litmus turns blue, in acid solution, red: widely used as a chemical indicator. [1495 1505; earlier lytmos < ON litmosi dye moss,… …   Universalium

  • litmus — noun Etymology: Middle English litmose, of Scandinavian origin; akin to Old Norse litmosi herbs used in dyeing, from litr color (akin to Old English wlite brightness, appearance) + mosi moss; akin to Old English mōs moss Date: 14th century 1. a… …   New Collegiate Dictionary

  • litmus — noun a) A dyestuff extracted from certain lichens, that changes color when exposed to pH levels greater than or less than certain critical levels. b) A simple test of acidity in a liquid using litmus, usually in the form of litmus paper. Syn:… …   Wiktionary

  • litmus — /ˈlɪtməs / (say litmuhs) noun a colouring substance obtained from certain lichens, especially Roccella tinctoria. In alkaline solution litmus turns blue, in acid solution red; hence it is widely used as an indicator, especially in the form of… …   Australian English dictionary

  • litmus — n. a dye obtained from lichens that is red under acid conditions and blue under alkaline conditions. Phrases and idioms: litmus paper a paper stained with litmus to be used as a test for acids or alkalis. Etymology: ME f. ONorw. litmosi f. ON… …   Useful english dictionary