A time-unit of innumerable years-the time which is measured through the equivalence with Palya (cylindrical pit or vessel) (which is filled with hair and emptied); the time taken to empty such Palya cannot be computed in number.
jaṃ kālappamāṇaṃ ṇa sakkai ghettoṃ taṃ uvamiyaṃ bhavati, dhaṇṇapalla iva teṇa uvamā jassa taṃ pallovamaṃ bhaṇṇati.
(Anu 419 Cū p. 57)
See - Palya, Adhvā Palyopama, Uddhāra Palyopama, Kṣetra Palyopama.