the exponent indicating the power to which a fixed number, the base, must be raised to obtain a given number or variable. It is used esp to simplify multiplication and division: if a x = M, then the logarithm of M to the base a (written log a M) is xOften shortened to: log See also common logarithm, natural logarithm
Word Origin for logarithm
C17: from New Latin logarithmus, coined 1614 by John Napier, from Greek logos ratio, reckoning + arithmos number
1610s, Modern Latin logarithmus, coined by Scottish mathematician John Napier (1550-1617), literally "ratio-number," from Greek logos "proportion, ratio, word" (see logos) + arithmos "number" (see arithmetic).
The power to which a base must be raised to produce a given number. For example, if the base is 10, then the logarithm of 1,000 (written log 1,000 or log10 1,000) is 3 because 103 = 1,000. See more at common logarithmnatural logarithm.