litmus_test
1. [ noun ] (chemistry,color) 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
Synonyms: litmus
Related terms: acid-base_indicator coloring_material litmus_paper litmus_paper
2. [ noun ] (education) a test that relies on a single indicator
Examples:

"her litmus test for good breeding is whether you split infinitives"

Related terms: examination
Similar spelling:   litmus_paper