(pl. axes /-siːz/ )
1
- an imaginary line about which a body rotates（转动所绕的）轴线：
the Earth revolves on its axis once every 24 hours.
地球每24小时绕轴线自转一周。
1.1
- Geometry an imaginary straight line passing through the centre of a symmetrical solid, and about which a plane figure can be conceived as rotating to generate the solid【几何】（对称）轴。
1.2
- an imaginary line which divides something into equal or roughly equal halves, especially in the direction of its greatest length中心轴。
2
- Mathematics a fixed reference line for the measurement of coordinates【数】坐标轴。
3
- a straight central part in a structure to which other parts are connected（连接其他部分的）中心部分。
3.1
- Botany the central column of an inflorescence or other growth【植】体轴; 茎轴。
3.2
- Zoology the skull and backbone of a vertebrate animal【动】中轴。
4
- Anatomy the second cervical vertebra, below the atlas at the top of the backbone【剖】枢椎, 第二颈椎。
5
- an agreement or alliance between two or more countries that forms a centre for an eventual larger grouping of nations（国家间的）联盟（形成实际拥有更多成员国的国家联合体的中心）：
the AngloAmerican axis.
英美联盟。
5.1
the Axis
the alliance of Germany and Italy formed before and during the Second World War, later extended to include Japan and other countries轴心国（第二次世界大战之前和期间形成的德意联盟, 后有日本及其他国家加入）：as modifier the Axis Powers.轴心国。
词源
late Middle English: from Latin， 'axle， pivot'.