Mathematics. the decimal part of a common logarithm. Compare characteristic( def 3a ).
Obsolete. an addition of little or no importance, as to a literary work.
Origin: 1860–65; < Latin, variant of mantisa addition, makeweight, said to be from Etruscan; logarithmic mantissa so called because it is additional to the characteristic or integral part (term introduced by H. Briggs)
mantissa (mān-tĭs'ə) Pronunciation Key
The part of a logarithm to the base ten that is to the right of the decimal point. For example, if 2.749 is a logarithm, .749 is the mantissa. Compare characteristic.
1. The part of a floating point number which, when multiplied by its radix raised to the power of its exponent, gives its value. The mantissa may include the number's sign or this may be considered to be a separate part. 2. The fractional part of a logarithm. (1996-06-15)