anoestrus vs anestrum

anoestrus and anestrum both are nouns.

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

As nouns, anoestrus and anestrum are synonyms defined as:

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

Other synonyms of anoestrus include anestrus, anoestrum.

anoestrus (noun)	anestrum (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