1. In a sound state of mind; mentally competent and in control of one's faculties.
Usage: Usually used in the phrase 'compos mentis' (Latin); the English adjective 'compos' alone is rare and formal/legal.

Examples

• The court determined that the defendant was compos mentis at the time of the incident.
• Despite his age, the elderly man remained compos and fully aware of his surroundings.
• The judge questioned whether the witness was compos enough to testify reliably.
• She was declared compos mentis by the medical examiner.
• The defendant's mental state was questioned, but experts found him to be compos.