diametrical opposition vs antipodal opposition

diametrical opposition and antipodal opposition both are nouns.

Word	Noun	Adjective	Verb	Adverb
diametrical opposition	Yes	No	No	No
antipodal opposition	Yes	No	No	No

As nouns, diametrical opposition and antipodal opposition are synonyms defined as:

diametrical opposition and antipodal opposition: the relation of opposition along a diameter

Other synonyms of diametrical opposition include antipodal.

diametrical opposition (noun)	antipodal opposition (noun)
the relation of opposition along a diameter	the relation of opposition along a diameter