number/tʁi.ljɔ̃/
quintillion (10¹⁸); trillion (10¹²)
From tri- (“three”) + -illion, from million; i.e. a million million million. Coined by Jehan Adam in 1475 as trimillion. Rendered as tryllion by Nicolas Chuquet in 1484, in his article “Triparty en la science des nombres”.