A time-unit of innumerable years.
It is of two kinds - 1. Vyāvahārika (empirical), 2. Sukṣma (subtle).
Vyāvahārika Adhvā Palyopama - There is a cylindrical pit (or vessel) measuring one Yojana (1Yojana=7.88 mile) each in length, breadth and height, and with a circumference of slightly more than three Yojanas. It is made cram-full with the billions of hair-tips of the children of the age of one day upto seven days. Every hundred years, a single hair is removed from it. The total period of time that elapses for emptying it completely is called Vyāvahārika Adhvā Palyopama. It is of no use (purpose); only for the sake of propounding, it is propounded.
The definition of "Sukṣma Adhvā Palyopama" is as follows: each hair tip (referred to in the above definition) is cut into innumerable pieces and the cylindrical vessel of the size mentioned above is made cram-full with these hair-pieces After every hundred years, a single piece is removed from the vessel. The total period of time that elapses for emptying it completely is called
"Sukṣma Adhvā Palyopama".
tattha ṇaṃ jese vāvahārie, sejahānāmae palle siyā joyaṇaṃ āyāma-vikkhaṃbheṇaṃ, joyaṇaṃ uḍḍham uccatteṇaṃ, taṃ tiguṇaṃ savisesaṃ parikkheveṇaṃ, se ṇaṃ palle - Gāhā-
egāhiya-beyāhiya-teyāhiya, ukkoseiiatn sattarattapariidhāṇaṃ.
sammaṭṭhe sannicite, bharie vālaggakoḍīṇaṃ... te ṇaṃ vālagge no aggī ḍahejjā, no vāū harejjā, no kucchejjā, no palividdhaṃsejjā, no pūiattāe havva-māgacchejjā. tao ṇaṃ vāsasae-vāsasae gate egamegaṃ vālaggaṃ avahāya jāvaieṇaṃ kāleṇaṃ se palle kliīṇe mīrae nilleve niṭṭhie bhavai. sidiume addhāpaliovame: se jahānāmae palle siyā-joyaṇaṃ āyāmavikkhaṃbheṇaṃ, joyaṇaṃ uḍḍham uccatteṇaṃ, taṃ tiguṇaṃ savisesaṃ parikkheveṇaṃ; se ṇaṃ palle Gāhā-
egāhiya-beyāhiya-teyāhiya, ukkoseṇaṃ sattarattaparūḍhaṇaṃ.
samaṭṭhe sannicitte, bharie vālaggakoḍiṇaṃ.. tattha ṇaṃ egamege vālagge asaṃkhejjāiṃ khaṃḍāiṃ kajjai, te ṇaṃ vālagge diṭṭhīogāhaṇāo asaṃkhejjaibhāgamettā suhnmassa paṇagajīvassa sartrogāhaṇāo asaṃkhejjaguṇā. te ṇaṃ vālagge no aggī ḍahejjā,... tao ṇaṃ vāsasae-vasasae gate egamegaṃ vālaggaṃ avahāya jāvaieṇaṃ kāleṇaṃ se palle khīṇe nīrae nilleve niṭṭhie bhavai. se taṃ suhume addhāpaliovame.
(Anu 427,429, 431)