Spousal abuse was the systematic mistreatment of an individual by their husband or wife.
In 2365, Data, while pretending to be Sherlock Holmes in the holoprogram Sherlock Holmes Program 3A, described a murder victim as having been abusive to his common law wife prior to his incarceration. (TNG: "Elementary, Dear Data")
In 2370, while attempting to discern the reason for Miles O'Brien's criminal behavior against the Cardassians, Kovat asked if spousal abuse might be responsible. O'Brien replied in the negative, saying his wife was very supportive of him. (DS9: "Tribunal")
Ijarna, an inhabitant of Deep Space 9, was a frequent victim of abuse at the hands of his wife. In 2373, after another assault wound up in the criminal activity report, Kira Nerys wondered aloud why he stayed with her. Odo explained that the same night, he found them together behind the information kiosk committing an act of public lewdness. Kira responded, "That answers my question." (DS9: "Crossfire")
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