Mediate (indirect) organ of valid knowledge-
1.That Pramāṇa (organ of valid knowledge), which lacks in vividness; and which depends upon the sense-organs and mind.
aviśadaḥ parokṣam.
(Pramī 1.2.1)
parasāhāyyāpekṣaṃ pramāṇamaspaṣṭatvāt parokṣam.
(Bhikṣu 3.1 Vṛ)
2.That cognition, which is not directly attained through the soul itself, but through Hetu (statement of Sādhana (proban or minor term)) etc., and through the dependence on the senseorgans and the mind.
egaṃteṇa parokkhaṃ liṃgiyaṃ...
(ViBhā 95)
See Parokṣajñāna.