In mathematics, the fractional part of a logarithm. Technical term used mainly in academic contexts.
significand
In computing, the part of a floating-point number that represents its significant digits. Technical term.
浮動小数点数の仮数部は有効数字を保持する。
The significand of a floating-point number holds the significant digits.
The mantissa of a logarithm refers to the part after the decimal point.
Compound of 仮数 (kasū, 'mantissa' or 'significand') and 部 (bu, 'part'). The exact historical derivation is uncertain; the term is a modern technical coinage.