most significant digit; MSD
Computing term for the leftmost non-zero digit in a number representation.
The most significant digit represents the largest place value of a number.
最小有効数字 (least significant digit) is the rightmost digit, opposite of 最大有効数字.
Compound of 最大 (maximum) + 有効 (effective) + 数字 (digit), a direct translation of the English computing term 'most significant digit'.