Webster's Revised Unabridged Dictionary · 1913

Numerator

Numerator , noun

[Latin numerator: compare French numérateur.]

1.
One who numbers.
2.
(Mathematics) The term in a fraction which indicates the number of fractional units that are taken.

In a vulgar fraction the numerator is written above a line; thus, in the fraction f (five ninths) 5 is the numerator; in a decimal fraction it is the number which follows the decimal point. See Fraction.