Saccavibhaṅgasuttantabhājanīya › Dukkhaariyasacca

Abhidhammapiṭaka · Vibhaṅga · Vol. 35 · Section 147

[147] Therein, what is aging (jarā)? That which, for the various beings in the various classes of beings, is aging, agedness, brokenness of teeth, grayness of hair, wrinkledness of skin, the dwindling of the life span, the ripening of the faculties (indriya) — this is called aging.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.