Axis
Pivotal Part
noun, suffix
The kanji and the word are exactly the same. That means they share meanings as well.
Literally, 軸 can refer to a physical axis, like the shaft something rotates around. Figuratively, it describes the pivotal part of something, like the central figure in a project, the core idea of a discussion, or the core belief that shapes who you are.
The reading is the same as the one you learned with the kanji.
地軸の延長が北方で天球と交わる点で会いましょう。
Let's meet up at the intersection of the earth's axis and the celestial sphere in the Arctic.