litmus

noun lit·mus \ ˈlit-məs \

Definition of litmus

1 : a coloring matter from lichens that turns red in acid solutions and blue in alkaline solutions and is used as an acid-base indicator
2 : the critical factor in a litmus test; also : litmus test

Recent Examples of litmus from the Web

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Origin and Etymology of litmus

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


Medical Dictionary

litmus

noun lit·mus \ ˈlit-məs \

medical Definition of litmus

: a coloring matter from lichens that turns red in acid solutions and blue in alkaline solutions and is used as an acid-base indicator

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