litmus paper

English Thesaurus

1. unsized paper treated with litmus for use as an acid-base indicator (noun.substance)

hypernym	:	paper,
definition	:	a material made of cellulose pulp derived mainly from wood or rags or certain grasses (noun.substance)

substance holonym	:	litmus, litmus test,
definition	:	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 (noun.substance)