n.
Pronunciation: ' ē - ə -s ə n
Variant: also eo · sine \ -s ə n, - ˌ s ē n \
Function: noun
Etymology: International Scientific Vocabulary, from Greek ē ō s dawn
Date: 1866
1 : a red fluorescent dye C 20 H 8 Br 4 O 5 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