Technical term used in geometry or crystallography to describe points or positions on opposite sides of a sphere or crystal. Rare in everyday language.
See also: 対心
結晶学では、対心的な位置にある原子を考慮する必要がある。
In crystallography, it is necessary to consider atoms at antipodal positions.
Compound of 対心 (antipodes) + 的 (adjectival suffix). The exact historical derivation is uncertain, but the term is used in technical contexts.