"Logarithm": 1. The mathematical function which is the inverse of "raising to the power of". Usually abbreviated to "log". For example working with logarithms to the base 10: log10 (100) = 2And 102 = 100More generally with logarithms to the base n: logn (x) = the power which, when 'n' is raised to it = xFor example 10 (log10 (x) ) = xAnd more generally n (logn (x) ) = x2. The logarithm to the base 10.