non-terminating decimal; infinite decimal
Rare mathematical term for a decimal that does not terminate. The more common term is 尽数 (じんすう) for terminating decimals, with 不尽数 as its opposite. Used in technical contexts.
See also: 尽数
A non-terminating decimal is a decimal whose fractional part continues infinitely.
Compound of 不 (fu, 'not') + 尽数 (jinsū, 'terminating decimal'). The exact historical derivation is uncertain, but the term follows standard Sino-Japanese word formation patterns.