A generic word for a very Large Number. The term has no well-defined mathematical meaning. Conway and Guy (1996) define the th zillion as in the American system ( , , , ...) and in the British system ( , , , ...). Conway and Guy (1996) also define the words n-plex and n-minex for and , respectively.
See also Large Number
Conway, J. H. and Guy, R. K. The Book of Numbers. New York: Springer-Verlag, pp. 13-16, 1996.