impotentia
Impotentia is a Latin term that historically referred to a lack of power or ability. In a legal context, particularly in historical English law, it described a condition where a person was legally incapable of performing certain actions or holding certain rights due to a physical or mental impediment. This could include a man's inability to perform the feudal duties of knighthood or to participate in legal proceedings. The concept was not necessarily about a medical condition as understood today, but rather about a legal status of helplessness or inability to act.
In more modern, though still historical, usage, the term impotentia was often used interchangeably with impotence,