A red fluorescent dye resulting from the action of bromine on fluorescein; used in cosmetics and as a biological stain for studying cell structures WordNet 3.0 & Open English WordNet

Eosin is the name of several fluorescent acidic compounds which bind to and form salts with basic, or eosinophilic, compounds like proteins containing amino acid residues such as arginine and lysine, and stains them dark red or pink as a result of the actions of bromine on eosin. Wikipedia

Groups of chemical compound used as dyes Wikidata

A red fluorescent dye resulting from the action of bromine on fluorescein; used in cosmetics and as a biological stain for studying cell structures. OmegaWiki

A fluorescent dye produced by the reaction of bromine with fluorescein. Wiktionary

A red, acidic dye commonly used in histological stains. Wiktionary

Red, acidic dye. Wiktionary (translation)