decimal fraction
noun
: a fraction (such as .25 = ²⁵/₁₀₀ or .025 = ²⁵/₁₀₀₀) or mixed number (such as 3.025 = 3²⁵/₁₀₀₀) in which the denominator is a power of 10 usually expressed by use of the decimal point
Word History
First Known Use
1660, in the meaning defined above