natural number

from WordNet (r) 3.0 (2006)

natural number
    n 1: the number 1 and any other number obtained by adding 1 to
         it repeatedly

from The Free On-line Dictionary of Computing (8 July 2008)

natural number

   <mathematics> An {integer} greater than or equal to zero.  A
   natural number is an {isomorphism class} of a finite set.

   (1995-03-25)