anestrus vs anoestrum

anestrus and anoestrum both are nouns.

Word	Noun	Adjective	Verb	Adverb
anestrus	Yes	No	No	No
anoestrum	Yes	No	No	No

As nouns, anestrus and anoestrum are synonyms defined as:

anestrus and anoestrum: applies to nonhuman mammals: a state or interval of sexual inactivity between two periods of estrus

Other synonyms of anestrus include anestrum, anoestrus.

anestrus (noun)	anoestrum (noun)
applies to nonhuman mammals: a state or interval of sexual inactivity between two periods of estrus	applies to nonhuman mammals: a state or interval of sexual inactivity between two periods of estrus