Knower of three sciences- One who is conversant with three sciences, viz., (1) knowledge of past life (2) knowledge of birth and death (3) knowledge of the annihilation of the influx (of Kanna) (i.e., āsravaksaya).
pūrvajanmajnānaṃ janmamaraṇayorjnānaṃ āsravakṣayajnānaṃ ceti tisro vidyāḥ. etāsāṃ vidyānām jñātā trividyo bhavati.
(ĀBhā 3.28)