Renunciation of food by undertaking fast unto death, after rendering the body suitable for such fasting through Saṃlekhanā (scraping penance unto death, i.e., emaciation of passions by a graded course of penance (fasting)).
paścimaivāmaṃgalaparihārārthamapaścimā maraṇaṃ-prāṇatyāgalakṣaṇam... maraṇamevānto maraṇāntastatra bhavā māraṇāntikī, saṃlikhyate-kṛślkriyate'nayā śanrakaṣāyādīti saṃlekhanā-tayorviśeṣalakṣaṇā tataḥ karmadhārayād apaścimamāraṇāntikasaṃlekhanā.
(Bhaga 7.35 Vṛ)