litmus English · revision 1668

+ ==Pronunciation==

+ * IPA: /ˈlɪtməs/^(Wiktionary)

+

+ ==Etymology==

+ It comes from Middle English ''litmose'',^(AHD)^(MW Collegiate)^(RHWU) of Scandinavian origin;^(AHD)^(Barnhart 1995)^(Etymonline)^(MW Collegiate) compare [[non|litmosi|t=herbs used in dyeing]],^(AHD)^(MW Collegiate)^(RHWU) from ''litr'' “color, dye”^(AHD)^(Etymonline)^(MW Collegiate)^(RHWU) and ''mosi'' “moss”.^(AHD)^(Barnhart 1995)^(Etymonline)^(MW Collegiate)^(RHWU) Barnhart and Etymonline say the word is also partly from Middle Dutch ''lijkmoes'' or ''lēcmoes'',^(Barnhart 1995)^(Etymonline) whose first element Barnhart connects with [[leak]].^(Barnhart 1995) It is related to [[moss]].^(Etymonline)^(MW Collegiate)

+

+ ==Earliest recorded meaning==

+ A blue coloring matter obtained from lichens (1320 as ''lykemose'' and 1324–25 as ''litemose'' in Barnhart, but 1502 in the OED).^(Barnhart 1995)^(OED 1989)

+

+ ==Semantic evolution==

+ The dye is naturally blue, turns red in acid and becomes blue again in alkali,^(Etymonline)^(RHWU) and so came to be used as a chemical indicator.^(RHWU) ''Litmus paper'', treated with the dye, is recorded from 1803.^(Barnhart 1995)^(Etymonline) From its use in chemistry came the figurative ''litmus test'', a single decisive test, from 1957.^(Barnhart 1995)^(Etymonline)

+

+ ==Timeline==

+ * 1320 – ''lykemose'' (Barnhart).^(Barnhart 1995)

+ * 1324–25 – ''litemose'' (Barnhart).^(Barnhart 1995)

+ * 1495–1505 – Random House's dating.^(RHWU)

+ * 1803 – ''litmus paper''.^(Barnhart 1995)^(Etymonline)

+ * 1957 – ''litmus test'', figurative.^(Barnhart 1995)^(Etymonline)

+

+ ==Modern meaning==

+ ===Noun===

+ # A blue powder obtained from certain [[lichen|alt=lichens]], which turns red in [[acid]] solutions and blue in [[alkali|alt=alkaline]] ones, used as an [[indicator]].^(AHD)^(MW Collegiate)^(RHWU)^(Wiktionary)

+ # A [[litmus test]]; the deciding factor in such a test.^(MW Collegiate)^(Wiktionary)

+

+ ==Word family==

+ * [[litmus paper]]

+ * [[litmus test]]

+

+ ==Related words==

+ * [[moss]]

+ * [[lichen]]

+ * [[leak]]

+

+ ==References==

+ {{reflist}}