Resorcin

noun

1. A colorless crystalline phenol, C6H4(OH)2.
2. A colorless crystalline substance of the phenol series, obtained by melting certain resins, as galbanum, asafetida, etc., with caustic potash. It is also produced artificially and used in making certain dyestuffs, as phthaleïn, fluoresceïn, and eosin.
3. A crystalline substance of the phenol series, obtained by melting certain resins with caustic potash, and sometimes used in dyestuffs.