## As nouns the difference between **abscissa** and **abscissae**

is that

**abscissa** is (geometry) the first of the two terms by which a point is referred to, in a system of fixed rectilinear coordinate (cartesian coordinate) axes the abscissa is also known as the "x" coordinate of a point, shown on the horizontal line, with the ordinate, also known as the "y" coordinate, shown on the vertical line

[ while ]**abscissae** is .