(a) Located opposite to or directed away from the mouth of an invertebrate; esp. applied to the surface (or to the structures on it) opposite that bearing the mouth and proximal ends of the ambulacral grooves of an echinoderm; or to the part of an echinoderm theca or plate directed away from the mouth (directed downward in an edrioasteroid). Cf: adoral. (b) Toward the underside of a conodont element; e.g. "aboral edge", "aboral groove", or "aboral attachment scar". Ant: oral.