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 

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