noun An imaginary line around which an object spins (an axis of rotation) or is symmetrically arranged (an axis of symmetry).
The Earth rotates once a day on its axis
noun 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 The second cervical vertebra of the spine
noun An imaginary, visualized plane separating two morphologically similar parts of an organism
noun A form of classification and descriptions of mental disorders or disabilities used in manuals such as the DSM (Diagnostic and Statistical Manual of Mental Disorders)
noun The main stem or central part about which organs or plant parts such as branches are arranged
noun An alliance or coalition.
noun The centre of attention within a process (e.g. the axis of investigation)