menstruum vs catamenia

menstruum and catamenia both are nouns.

Word	Noun	Adjective	Verb	Adverb
menstruum	Yes	No	No	No
catamenia	Yes	No	No	No

As nouns, menstruum and catamenia are synonyms defined as:

menstruum and catamenia: the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause

Other synonyms of menstruum include flow, menses, menstruation, period.

menstruum (noun)	catamenia (noun)
the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause	the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause
(archaic) a solvent