WordNet
of unsound mind
adj. not of sound mind, memory, or understanding; in law, not competent to go to trial [syn: non compos mentis(p), of unsound mind(p)]
Usage examples of "of unsound mind".
They should realize that the values they are taught are the values of particular men, and often, unfortunately, of men who, long ago, were short-lived, ignorant, uninformed, unhealthy and quite possibly of unsound mind.
There was no question of unsound mind, the old man was as sane as anybody.
I knew that she'd try it by every means in her power, but she couldn't claim the grandfather was of unsound mind, and there's no question of undue influence.