: the horizontal coordinate of a point in a plane Cartesian coordinate system obtained by measuring parallel to the x-axis compare ordinate
Illustration of abscissa
AP abscissa of point P
Word History
Etymology
borrowed from New Latin (short for linea abscissa, literally, "cut-off line"), going back to Latin, feminine of abscissus, past participle of abscindere "to tear off or away," from ab-ab- + scindere "to split, separate, tear apart," going back to Indo-European *sḱhi-n-d-, nasal present formation from the base *sḱhei̯̯d- "split, separate" — more at shed entry 1