The Oxford Thesaurus An A-Z Dictionary of Synonyms - sex n.

1) gender: It is difficult to determine the sex of some of the lower animals. 2) sexual intercourse or relations, coitus, coition, mating, copulation, (sexual) congress or union, intimacy, lovemaking, making love, coupling, Colloq making out, going to bed, shacking up, Slang having it away, Taboo slang screwing, shafting, shagging, fucking, Chiefly Brit bonking: They feel that there is too much sex and violence on television these days.