litmus
[ lit-muh s ]
/ ˈlɪt məs /
noun
a blue coloring matter obtained from certain lichens, especially Roccella tinctoria. In alkaline solution litmus turns blue, in acid solution, red: widely used as a chemical indicator.
Origin of litmus
1495–1505; earlier
lytmos < Old Norse
litmosi dye-moss, equivalent to
lit- color, dye +
mosi moss
Words nearby litmus
litigate,
litigation,
litigation friend,
litigator,
litigious,
litmus,
litmus paper,
litmus test,
litotes,
litre,
litt. b.
Example sentences from the Web for litmus
British Dictionary definitions for litmus
litmus
/ (ˈlɪtməs) /
noun
a soluble powder obtained from certain lichens. It turns red under acid conditions and blue under basic conditions and is used as an indicator
Word Origin for litmus
C16: perhaps from Scandinavian; compare Old Norse
litmosi, from
litr dye +
mosi moss
Medical definitions for litmus
litmus
[ lĭt′məs ]
n.
A water-soluble blue powder derived from lichens that changes to red with increasing acidity and to blue with increasing basicity.
Scientific definitions for litmus
litmus
[ lĭt′məs ]
A colored powder, obtained from certain lichens, that changes to red in an acid solution and to blue in an alkaline solution. Litmus is a mixture of various closely related heterocyclic organic compounds.♦ Litmus is typically added to paper to make litmus paper, which can be used to determine whether a solution is basic or acidic by dipping a strip of the paper into the solution and seeing how the paper changes color.
Cultural definitions for litmus
litmus
[ (lit-muhs) ]
In chemistry, a kind of paper used to tell whether a solution is an acid or a base. Acids turn blue litmus paper red; bases turn red litmus paper blue. Other testing paper or sophisticated instruments can be used to measure the pH of a solution more precisely.
notes for litmus
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.”