What is Extremis?

Legal Definition
When a person is sick beyond the hope of recovery, and near death, he is said to be in extremism.

2. A will made in this condition, if made without undue influence, by a person of sound mind, is valid.

3. The declarations of persons in extremis, when made with a full consciousness of approaching death, ate admissible in evidence when the death of the person making them is the subject of the charge, and the circumstances of the death the subject of such declarations. 2 B. & C. 605 S. C. 9 Eng. C. L. Rep..196; and see 15 John. 286; 1 John. Rep. 159; 2 John. R. 31; 7 John. 95; 2 Car. Law. Repos. 102; 5 whart, R. 396-7.
-- Bouviers Law Dictionary
Legal Definition
When a person is sick beyond the hope of recovery, and near death, he ls said to be in extremis.
-- Black's Law Dictionary
Legal Definition
-- Ballentine's Law Dictionary