Source : Webster's Revised Unabridged Dictionary (1913)

Abaxial \Ab*ax"i*al\ ([a^]b*[a^]ks"[i^]*al), Abaxile \Ab*ax"ile\
   ([a^]b*[a^]ks"[i^]l),a. [L. ab + axis axle.] (Bot.)
   Away from the axis or central line; eccentric. --Balfour.

Source : WordNet®

abaxial
     adj : facing away from the axis of an organ or organism; "the
           abaxial surface of a leaf is the underside or side
           facing away from the stem" [syn: {dorsal}] [ant: {adaxial}]