| 1. | Arithmetic. the term of a fraction, usually above the line, that indicates the number of equal parts that are to be added together; the dividend placed over a divisor: The numerator of the fraction 2/3 is 2. Compare denominator (def. 1). |
| 2. | a person or thing that numbers. |
In mathematics, the number that appears on the top of a fraction. In the fraction 2/3, the numerator is 2. (Compare denominator.)