noun, noun which may take the genitive case particle 'no'
opposite sex
General term for the other sex; often contrasted with 同性 (same sex). Used in both noun and adjectival (の) positions.
See also: 同性
異性の友達が少ない。
I have few friends of the opposite sex.
異性に興味を持つ年
It's an age when you become interested in the opposite sex.
noun, noun which may take the genitive case particle 'no'
isomerism
Chemistry term for compounds with the same molecular formula but different structures. Rare in everyday language.
異性体は化学的性質が異なる。
Isomers have different chemical properties.