Following up on Madhav's inquiry: SuS'aa 3.5 has the following: tatra s'ukrabaahulyaat pumaan, aartavabaahulyaat strii, saamyaadubhayor napumsakam This may be a medical explanation of the grammatical definition; or perhaps the grammatical explanation is another way of stating the medical definition. An interesting topic anyway one looks at it. Ken Zysk