Source : Webster's Revised Unabridged Dictionary (1913)

Catamenial \Cat`a*me"ni*al\ (-al), a. [Gr. ? monthly; kata`
   down, back, again + ? month.]
   Pertaining to the catamenia, or menstrual discharges.

Source : WordNet®

catamenial
     adj : of or relating to menstruation or the menses; "menstrual
           period" [syn: {menstrual}]