- noun the power to which a base must be raised to equal a given number
- noun the power by which a base number has to be raised to give a certain number
- The power to which a base, such as e or 10, must be raised, to produce a given number. For example, loge y = n, where e is the base, y is the power, and n is the resulting number. A logarithm has two portions, the characteristic, which is an integer, and the mantissa, which is a decimal. Its abbreviation is log.