- Proper noun. The alliance group before and during World War II consisting of Germany, Italy, Japan, and allied countries.
- Noun. (geometry) An imaginary line around which an object spins (an axis of rotation) or is symmetrically arranged (an axis of symmetry).
- Noun. (mathematics) A fixed one-dimensional figure, such as a line or arc, with an origin and orientation and such that its points are in one-to-one correspondence with a set of numbers; an axis forms part of the basis of a space or is used to position and locate data in a graph (a coordinate axis).
- Noun. (anatomy) The second cervical vertebra of the spine.
- Noun. ''Axis axis'', a deer native to Asia.