non compos mentis vs of unsound mind

non compos mentis and of unsound mind both are adjectives.

Word	Noun	Adjective	Verb	Adverb
non compos mentis	No	Yes	No	No
of unsound mind	No	Yes	No	No

As adjectives, non compos mentis and of unsound mind are synonyms defined as:

non compos mentis and of unsound mind: not of sound mind, memory, or understanding; in law, not competent to go to trial

non compos mentis (adjective)	of unsound mind (adjective)
not of sound mind, memory, or understanding; in law, not competent to go to trial	not of sound mind, memory, or understanding; in law, not competent to go to trial