an imaginary line through the centre of an object, around which the object turns 轴（旋转物体假想的中心线） Mars takes longer to revolve on its axis than the Earth. 火星自转一周的时间比地球长。 the earth’s axis of rotation 地球的旋转轴
Oxford Collocations Dictionaryadjective- horizontal
- vertical
- x
- …
- along an/the axis
- on an/the axis
- an axis of rotation
- an axis of symmetry
- (specialist)
a fixed line against which the positions of points are measured, especially points on a graph 坐标轴 
the vertical/horizontal axis 纵／横坐标轴 The real wage is measured along the horizontal axis and the quantity of labour is measured along the vertical axis. 实际工资沿横轴计算，劳动量沿纵轴计算。 The main road is on a north-south axis. 主干道位于南北轴线上。 the speed is measured along the horizontal axis 速度用横轴线来表示。
Oxford Collocations Dictionaryadjective- horizontal
- vertical
- x
- …
- along an/the axis
- on an/the axis
- an axis of rotation
- an axis of symmetry
- (
geometry 几何 a line that divides a shape into two equal parts 对称中心线（将物体平分为二） 
Oxford Collocations Dictionaryadjective- horizontal
- vertical
- x
- …
- along an/the axis
- on an/the axis
- an axis of rotation
- an axis of symmetry
- [usually singular] (formal)
an agreement or alliance between two or more countries that forms the centre for a larger grouping of nations 轴心（国与国之间的协议或联盟） the Franco-German axis 法德轴心
Word Originlate Middle English: from Latin, ‘axle, pivot’.