anestrum vs anoestrus

anestrum and anoestrus both are nouns.

Word	Noun	Adjective	Verb	Adverb
anestrum	Yes	No	No	No
anoestrus	Yes	No	No	No

As nouns, anestrum and anoestrus are synonyms defined as:

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

Other synonyms of anestrum include anestrus, anoestrum.

anestrum (noun)	anoestrus (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