eosin

noun

eo·​sin ˈē-ə-sən How to pronounce eosin (audio)
variants or less commonly eosine
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

Time Traveler
The first known use of eosin was in 1866

Dictionary Entries Near eosin

Cite this Entry

“Eosin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/eosin. Accessed 31 Oct. 2024.

Medical Definition

eosin

noun
eo·​sin ˈē-ə-sən How to pronounce eosin (audio)
variants also eosine
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

More from Merriam-Webster on eosin

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