DIAMETRICALLY (adverb) definition and synonyms | Macmillan Dictionary.

What is diametrically?

1 mathematics : of, relating to, or constituting a straight line segment passing through the center of a figure or body : located at the diameter (see diameter sense 1) 2 : completely opposed : being at opposite extremes in diametric contradiction to his claims two parties in diametric opposition on the issue.

Is diametric a noun?

of, relating to, or along a diameter.