[ 'mɛnstrʊəm ]
■ noun ( plural menstrua -strʊə )
1》 menses.
2》 archaic a solvent.
Origin
ME: from L., neut. of menstruus 'monthly', from mensis 'month'; sense 2 is by alchemical analogy between transmutation of metals into gold and the supposed action of menses on the ovum.