Source : Webster's Revised Unabridged Dictionary (1913)

Aboral \Ab*o"ral\, a. [L. ab. + E. oral.] (Zo["o]l.)
   Situated opposite to, or away from, the mouth.

Source : WordNet®

aboral
     adj : opposite to or away from the mouth; "the aboral surface of a
           starfish" [ant: {oral}]