antipodal

adj. diametrically opposite, polar; on the opposite side of the globe

The word antipode can be used to mean either the point on the surface of the earth or another celestial body that is diametrically opposite to a given point (usually used as a plural in this sense), or the exact opposite or contrary of something. It is a back-formed singular from the word antipodes, which originally was not plural.
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Noun
1. the relation of opposition along a diameter
(synonym) antipodal opposition, diametrical opposition
(hypernym) opposition
Adjective
1. relating to the antipodes or situated at opposite sides of the earth; "antodpodean latitudes"; "antipodal regions of the earth"; "antipodal points on a sphere"
(synonym) antipodean
(pertainym) antipodes

adj. antipodal, diametrically opposite

(a.)
Pertaining to the antipodes; situated on the opposite side of the globe.
  

(a.)
Diametrically opposite.