an imaginary line through the center of an object, around which the object turnsMars takes longer to revolve on its axis than the earth does.2(technical)a fixed line against which the positions of points are measured, especially points on a graphthe vertical/horizontal axisThe real cost is measured along the horizontal axis and the quantity of labor is measured along the vertical axis.The main road is on a north-south axis.3(geometry)a line that divides a shape into two equal partsan axis of symmetryThe axis of a circle is its diameter.4[usually singular] (formal) an agreement or alliance between two or more countriesthe Axis Powers of World War II
