The Collaborative International Dictionary
Menstruum \Men"stru*um\, n.; pl. E. Menstruums, L. Menstrua. 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.
Wiktionary
n. (plural of menstruum English)
WordNet
n. (archaic) a solvent
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 [syn: menstruation, menses, catamenia, period, flow]
[also: menstrua (pl)]
See menstruum