axial

adj

1. Relating to, resembling, or situated on an axis

   “The axial asymmetry of Mercury's inertia ellipsoid may result in a torque that counterbalances the tidal torque”

2. Belonging to the axis of the body, or to the axis of any appendage or organ

   “the axial skeleton”

   “the axial bones”

3. In the same direction as the axis, parallel to the axis.

   “The secondary xylem usually consists of axial and radial elements.”

4. (physical)Oriented parallel to the axis running through the centre of a cyclohexane ring, as opposed to equatorial. See Axial bond.

noun

1. A flight feather that appears between the primaries and secondaries on some birds.
2. A plane parallel to the surface of a tooth.