A sub-type of Āyuṣya (life-span-determining) Karma, due to the Udaya (rise) of which the Jīva (soul) undergoes the experience of the state of infernal being.
nārakādyāyuḥpudgalāndmtidayena nārakādyāyurvedayate.
(Prajñā 23.37 Vṛ Pa 463)
āyurevāyuṣkaṃ......tatra narakā utpattiyātanāsthānāni pṛthivlpariṇativiśeṣāstatsaṃbandhinaḥ sattvā api tātsthyānnarakāsteṣāmidamāynmārakatn.
(TaBhā 8.11 Vṛ p. 148)