traividya [tevijja] one possessing triple knowledge. An Arhat is endowed with triple knowledge, hence he is known as traividya. The triple knowledge includes knowledge of former births; knowledge of the future births of beings; and knowledge that uproots all depravities.

     Knowledge regarding impermanence, suffering and no-self is also known as triple knowledge.  

Buddhānusmṛti - A Glossary of Buddhist Terms

Lalita-Vistara. XXII. 289. Majjhima Nikāya. Tevijjavacchagotta. Saddharmapuṇḍarīkasūtram. V. 176.