Sallekhanā, “thinning out”, is the gradual reduction of food and drink by one facing death from age or incurable illness, with the permission of a teacher. Jains distinguish it sharply from suicide: it is undertaken without passion, as a final act of detachment, so that the soul may leave the body in equanimity.
Sallekhanā
The Jain vow of peaceful death by gradual fasting, taken when life is near its natural end.
Also: Sallekhana, santhara