a woman who is the dominant sexual partner in a sadomasochistic relationship
2.
a dominant woman
Word origin
C16: from Latin, fem of dominātor, from dominārī to be lord over
dominatrix in American English
(ˌdɑmɪˈneɪtrɪks)
US
nounWord forms: pluralˌdomiˈnatrixes or ˌdomiˈnatriˌces (ˈdɑmɪˈnætrəˌsiz)
a woman who subjects her masochistic sexual partner to bondage, the infliction of ritualistic punishments, etc.; specif., a prostitute who performs such acts for her customers