from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A water-soluble blue powder derived from certain lichens that changes to red with increasing acidity and to blue with increasing basicity.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A dyestuff extracted from certain lichens, that changes color when exposed to pH levels greater than or less than certain critical levels.
  • n. A simple test of acidity in a liquid using litmus, usually in the form of litmus paper.
  • n. A simple test of any attribute; a litmus test.

from the GNU version of the Collaborative International Dictionary of English

  • n. A dyestuff extracted from certain lichens (Roccella tinctoria, Lecanora tartarea, etc.), as a blue amorphous mass which consists of a compound of the alkaline carbonates with certain coloring matters related to orcin and orcein.

from The Century Dictionary and Cyclopedia

  • n. A peculiar coloring matter procured from Roccella tinctoria and some other lichens.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a coloring material (obtained from lichens) that turns red in acid solutions and blue in alkaline solutions; used as a very rough acid-base indicator


from The American Heritage® Dictionary of the English Language, 4th Edition

Middle English litemose (of Scandinavian origin; akin to Old Norse litmosi, dyer's herbs litr, color, dye + mosi, bog, moss) and Middle English lykemose (from Middle Dutch lijkmoes, variant of lēcmoes : lēken, to drip + moes, moss).

from Wiktionary, Creative Commons Attribution/Share-Alike License

1495, earlier lytmos, from Old Norse litmosi ("moss used for dyeing"), from lita ("to dye, stain"), from litr ("colour, dye, blee"), from Proto-Germanic *wlitiz, *wlituz (“appearance, blee”), from Proto-Indo-European *wel- (“to see”) + mosi ("moss"). Cognate with Old English wlite ("appearance, form, brightness, countenance"). More at moss.


  • ‡ The term litmus is often used to refer to a general and simple test: “Your vote on this issue is a litmus test of your political philosophy.


  • He said Angola had reached the point when soldiers would be quartered in camps and demobilized, which he called the litmus test for peace.

    ANC Daily News Briefing

  • This is what Israeli Democracy Looks Like '; yahooBuzzArticleSummary =' Article: Freedom of the press is often called the litmus test of democracy.

    Stop the Press! This is what Israeli Democracy Looks Like

  • MOLINEAUX: It's like hearing the word litmus test coming up in the next few months.

    CNN Transcript Jan 26, 2003

  • Because they knew full well the Tibetan people and Tibetan monks would not accept their choice, so instead of a puppet Lama who would mouth their message to believing Tibetans, they erected a built-in, long-term litmus test to root out monks and nuns and lamas who were sincere Tibetan Buddhist practitioners, since when they were forced to pledge allegiance to the Communist choice of reincarnation, the sincere ones would refuse, and so could be kicked out of their monasteries, imprisoned, tortured, and branded for life as "splittists."

    China Is Attempting to Wipe Out Buddhism

  • Let me move on quickly to this Republican proposal that some conservatives want but some are calling a litmus test -- ten points.

    CNN Transcript Dec 2, 2009

  • I want to talk about this so-called litmus test that Republicans, conservatives are being asked to take.

    CNN Transcript Dec 2, 2009

  • Mr. Kennedy will probably get to cast the deciding vote in a host of so-called litmus-test cases this fall, and most prominent among them could be the court's revisiting of detainee rights at Guantanamo Bay.

    All Eyes Are Again

  • It is easy to forget that, on so-called litmus-test issues, McCain has remained a safe Republican vote distinctly in tune with the hard right of his own party and constituents.

    Nothing Left to Fear

  • If the ore is strictly neutral the quantity of "acid" required to redden the litmus will be the same as the quantity of "soda" originally used.

    A Text-book of Assaying: For the Use of Those Connected with Mines.


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