diametrically


diametrically (http://definr.com/diametrically)

     adv : as from opposite ends of a diameter; "when two honest
           witnesses give accounts of the same event that differ
           diametrically, how can anyone prove that the evidence
           you gave was deliberately false?"; "three of these
           brushes were approximately 120 feet apart and the
           fourth diametrically opposite to one of the three"