'Diametrically' definitions:

Definition of 'diametrically'

(from WordNet)
adverb
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"

Definition of 'Diametrically'

From: GCIDE
  • Diametrically \Di*am"e*tric*al*ly\, adv. In a diametrical manner; directly; as, diametrically opposite. [1913 Webster]
  • Whose principles were diametrically opposed to his. --Macaulay. [1913 Webster]