/ Dictionary / Index A anestrus: Meaning and Definition of Find definitions for: an•es•trus Pronunciation: (an-es'trus), [key] — n. Zool. (of a female mammal) the interval of sexual inactivity between two periods of heat or rut. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: anestrus (Thesaurus) anestrous anethole Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language