from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The periodic state of sexual excitement in the female of most mammals, excluding humans, that immediately precedes ovulation and during which the female is most receptive to mating; heat.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Alternative spelling of oestrus.
New Latin, from Latin oestrus, frenzy, gadfly, from Greek oistros; see eis- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)