axo- Also axi-.
[Greek axōn, axis.]
This ending appears in a few biological terms: an axon is the long thread-like part of a nerve cell along which impulses are conducted from the cell body to other cells; an axoneme is the central strand of a cilium or flagellum. In architecture an axonometric projection is drawn on a plane inclined to each of the three principal axes of the object, so that it is three-dimensional but without perspective; something axisymmetric is symmetrical about an axis. Axiom, however, is from a different Greek word, axios, worthy.