-dex is a suffix used by:
(1) André Joyce for the operand 510, a verbalized Roman numeral DX, as in the number name (arithmonym), googodex = g(2, 1020, 510). This was re-spelled with the silent -h- infix for "formerly high", to -dhex to distinguish it from the secondary meaning. googol
(2) -dex is also a suffix exclusive to ExE, designed by Sbiis Saibian. Let N be a number expressed in ExE as Ea@. In this case (N)-dex = Ea#N. With this, Sbiis Saibian forms several derivative googolisms.