Abscissa

• POS: Noun
• HYPHEN: ab=scis=sa

CIDE DICTIONARY

Abscissa, n. [L., fem. of abscissus, p. p. of absindere to cut of. See Abscind.].

 One of the elements of reference by which a point, as of a curve, is referred to a system of fixed rectilineal coördinate axes.
"When referred to two intersecting axes, one of them called the axis of abscissas, or of X, and the other the axis of ordinates, or of Y, the abscissa of the point is the distance cut off from the axis of X by a line drawn through it and parallel to the axis of Y. When a point in space is referred to three axes having a common intersection, the abscissa may be the distance measured parallel to either of them, from the point to the plane of the other two axes. Abscissas and ordinates taken together are called coördinates. -- OX or PY is the abscissa of the point P of the curve, OY or PX its ordinate, the intersecting lines OX and OY being the axes of abscissas and ordinates respectively, and the point O their origin."  [1913 Webster]

OXFORD DICTIONARY

Abscissa, n. (pl. abscissae or abscissas) Math.
1 (in a system of coordinates) the shortest distance from a point to the vertical or y-axis, measured parallel to the horizontal or x-axis; the Cartesian x-coordinate of a point (cf. ORDINATE).
2 the part of a line between a fixed point on it and an ordinate drawn to it from any other point.

Etymology

mod.L abscissa (linea) fem. past part. of abscindere absciss- (as AB-, scindere cut)