eosin
noun
eo·sin ˈē-ə-sən 
variants or less commonly eosine
ˈē-ə-sən
-ˌsēn
1
: a red fluorescent dye C20H8Br4O5 obtained by the action of bromine on fluorescein and used especially in cosmetics and as a toner
also : its red to brown sodium or potassium salt used especially as a biological stain for cytoplasmic structures
2
: any of several dyes related to eosin
Word History
Etymology
International Scientific Vocabulary, from Greek ēōs dawn
First Known Use
1866, in the meaning defined at sense 1
Medical Definition
eosin
noun
eo·sin ˈē-ə-sən
variants also eosine
-sən -ˌsēn
-ˌsēn 1
: a red fluorescent dye C20H8Br405 obtained by the action of bromine on fluorescein and used especially in cosmetics and as a toner
also : its red to brown sodium or potassium salt used especially as a biological stain for cytoplasmic structures
2
: any of several dyes related to eosin