柯林斯詞典litmus /?l?tm?s/ 1. N a soluble powder obtained from certain lichens. It turns red under acid conditions and blue under basic conditions and is used as an indicator 石蕊 返回 litmus劍橋詞典a powder that is turned red by acid and blue by alkali 石蕊 litmus paper 石蕊試紙 a litmus test 石蕊測(cè)試 返回 litmus