axis
UK[ˈæksɪs]US[ˈæksɪs]
n
An imaginary line through the center of an object, around which the object turns
n
A fixed reference line for the measurement of coordinates, as in a graph
n
An alliance or agreement between two or more countries that forms a center for an eventual larger grouping of nations
Etymology
The word 'axis' was adopted directly into English from Latin, where it meant 'axle, pivot, or axis of the earth or sky'. The Latin term is traced back to the Proto-Indo-European root aks-, which also meant 'axis'. This root is the source for related words in other Indo-European languages, such as the Greek 'axon' (axle) and the Sanskrit 'aksha'. The core concept of a central line or pivot has remained remarkably stable from its ancient physical sense of a chariot's axle to its modern applications in geometry, physics, and geopolitics.
Analysis
The word 'axis' is a simplex loanword from Latin. It does not contain separable, meaningful morphemes within its modern English spelling.
Examples
The Earth rotates on its axis once every 24 hours.
Plot the data points along the vertical and horizontal axes.
The two nations formed the core axis of the military alliance.