MENSTRUUM

menstruation, menses, menstruum, catamenia, period, flow

(noun) the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause; “the women were sickly and subject to excessive menstruation”; “a woman does not take the gout unless her menses be stopped”--Hippocrates; “the semen begins to appear in males and to be emitted at the same time of life that the catamenia begin to flow in females”--Aristotle

menstruum

(noun) (archaic) a solvent

Source: WordNet® 3.1

Etymology

Noun

menstruum (plural menstruums or menstrua)

(chiefly, in the plural, historical) The menses; menstrual discharge. [from 14th c.]

(historical) A solvent. [from 16th c.]

Any liquid medium.

Source: Wiktionary

Men"stru*um, n.; pl. E. Menstruums, L. Menstrua. Etym: [L. menstruus. See Menstruous.]

Definition: Any substance which dissolves a solid body; a solvent. The proper menstruum to dissolve metal. Bacon. All liquors are called menstruums which are used as dissolvents, or to extract the virtues of ingredients by infusion or decoction. Quincy.

Note: The use is supposed to have originated in some notion of the old chemists about the influence of the moon in the preparation of dissolvents. Johnson.

Source: Webster’s Unabridged Dictionary 1913 Edition