Pertaining to or of the nature of an axis.Situated in an axis or in the axis.In anatomy, pertaining to the somatic as distinguished from the membral portions of the body; not appendicular.In geology, forming the axis, central dominating portion, or crest of a mountain-range.Sometimes axal.A nerve running in a special groove on the floor of the main brachial groove and proceeding from the aboral or dorsal nervous system. It sends branches to the muscles of the arms and to the supposed sensory endings in the ectoderm.The projection of the crystallographic axes of a given species, as used, for example, in the drawing of crystals.n. In mathematics, an axial pencil.