What is the term for reduced mental or physical ability in a legal context?

The term for reduced mental or physical ability in a legal context is "diminished capacity." This concept is significant in both criminal and civil law, particularly when assessing a person's ability to understand the nature of their actions or to form intent. Diminished capacity recognizes that an individual's mental state can affect their culpability or responsibility for an act. It often comes into play in cases where an individual may not be able to fully understand legal proceedings or the consequences of their actions due to mental illness or cognitive impairment.

While related terms such as "incapacitation," "disability," and "impairment" may describe various aspects of ability or functioning, they do not specifically capture the legal nuance of "diminished capacity," which focuses on how reduced ability affects a person's legal responsibility. For instance, incapacitation often refers to a state where someone cannot perform functions or make decisions at all, while disability can broadly encompass various physical and mental health conditions without necessarily addressing the component of legal responsibility. Impairment is a more general term that indicates a reduction in function or ability but does not inherently imply its legal implications. Therefore, diminished capacity is the most precise term when discussing reduced ability in a legal context.