(1) In the context of the Mahayana tenet system, a synonym for deepest truths. Specifically, in the Chittamatra system, the various voidnesses, true stoppings, and nirvana. (2) In the Buddhist medical system, hereditary, congenital diseases; genetic disorders.
Tibetan: ཡོངས་གྲུབ། yongs-grub
J. Hopkins: Thoroughly established phenomenon; thoroughly established [nature].