dom·i·na·trix 
(dŏm′ə-nātrĭks)
(dŏm′ə-nātrĭks)n. pl. dom·i·na·trix·es or dom·i·na·tri·ces (-nātrĭ-sēz′, -nə-trīsēz)
1. A woman who acts out the role of the dominating partner in a sadomasochistic relationship.
2. A woman regarded as overbearing.