coccin

from The Century Dictionary.

• noun A term applied to two aniline dyes, both of a red color, one of which, also termed safrosin, eosin scarlet, nopalin, and eosin BN, is dinitrobromfiuorescin, and the other, known as coccin 2B and as crocein 3BX, is the sodium salt of sulpho-α-azonaphthalin-sulpho-β-naphthol.