The Collaborative International Dictionary of English v.0.48:

Amenorrhoeal \A*men`or*rh[oe]"al\, a.
   Pertaining to amenorrhoea.
   [1913 Webster]

WordNet (r) 3.0 (2006):

amenorrhoeal
    adj 1: related to the suppression of normal menstrual flow for
           any reason other than pregnancy [syn: amenorrheic,
           amenorrhoeic, amenorrheal, amenorrhoeal]