A dominatrix was a term for a woman who took a dominant role in particular sexual activities.
In a debriefing on the missions of the USS Discovery with the holos at Federation Headquarters in 3189, Ensign Sylvia Tilly described one instance as occuring "after I got my hair blown out and became a Terran captain/dominatrix," referring to the time Discovery travelled to the mirror universe, and Tilly had to act as her mirror counterpart. (DIS: "Die Trying")