geometric mean

from WordNet (r) 3.0 (2006)

geometric mean
    n 1: the mean of n numbers expressed as the n-th root of their
         product

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

geometric mean

   <mathematics> The Nth {root} of the {product} of N numbers.

   If each number in a list of numbers was replaced with their
   geometric mean, then multiplying them all together would still
   give the same result.  The geometric mean thus gives an
   average "factor" in a context where numbers are multiplied
   together, e.g. compound interest.

   Wolfram (http://mathworld.wolfram.com/GeometricMean.html).

   (2007-03-16)