Definitions for octillionɒkˈtɪl yən
Random House Webster's College Dictionary
oc•til•lionɒkˈtɪl yən(n.)(pl.)-lions; -lion
(n.)a cardinal number represented in the U.S. by 1 followed by 27 zeros, and in Great Britain by 1 followed by 48 zeros.
(adj.)amounting to one octillion in number.
Origin of octillion:
1680–90; < F, =oct-oct - +-illion, as in million