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
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).(American Heritage® Dictionary of the English Language, Fourth Edition)
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. (Wiktionary)