Which term describes someone who is not of sound mind?

The term that describes someone who is not of sound mind is "non compos mentis." This Latin phrase specifically refers to a state of mental incapacity, indicating that a person is unable to manage their own affairs or think rationally due to mental illness or cognitive impairment. In legal contexts, "non compos mentis" can affect one's ability to enter contracts, make decisions, or represent themselves in legal matters.

The other terms listed do not relate to mental capacity. "Pendente lite" refers to a legal situation that is awaiting a decision or trial. "Parol" pertains to verbal agreements or statements, as opposed to written contracts. "Per capita" describes a method of distributing something, typically an estate, among individuals equally, without regard to lineage. Each of these terms carries a specific legal meaning that does not connect to the concept of someone being of unsound mind.