opposite-sex

The compound adjective "opposite-sex" is a modern English formation built from two distinct Latin-derived elements. "Opposite" originates from the Latin verb opponere, meaning "to set against," which itself combines the prefix ob- (against) and the verb ponere (to place). "Sex" comes directly from the Latin noun sexus, denoting the division into male and female. The compound logically combines these concepts to describe something pertaining to or involving the gender that is contrary or complementary to one's own, a term that gained prominence in sociological and legal contexts in the 20th century to specify relationships or dynamics between men and women.

Structure: opposite (contrary) + sex (gender) - opposite: From Latin oppositus, past participle of opponere (to place against), from ob- (against) + ponere (to place). Functions as an adjective/adverb meaning directly contrary or facing. - sex: From Latin sexus (state of being male or female, gender). Functions as a noun denoting biological gender.