[syn: diametric, diametrical, opposite, polar]
The Collaborative International Dictionary of English v.0.48:
Diametric \Di*am"e*tric\, Diametrical \Di*am"e*tric*al\, a.
   1. Of or pertaining to a diameter.
      [1913 Webster]
   2. As remote as possible, as if at the opposite end of a
      diameter; directly adverse.
      [1913 Webster]
WordNet (r) 3.0 (2006):
diametrical
    adj 1: related to or along a diameter; "the diametral plane"
           [syn: diametral, diametric, diametrical]
    2: characterized by opposite extremes; completely opposed; "in
       diametric contradiction to his claims"; "diametrical (or
       opposite) points of view"; "opposite meanings"; "extreme and
       indefensible polar positions" [syn: diametric,
       diametrical, opposite, polar]