carnal knowledge, coition, coitus, sex act, sexual congress, sexual intercourse, sexual relation, copulation, intercourse, relation, congress - the act of sexual procreation between a man and a woman; the man's penis is inserted into the woman's vagina and excited until orgasm and ejaculation occur

extramarital sex, free love - sexual intercourse between individuals who are not married to one another

incest - sexual intercourse between persons too closely related to marry (as between a parent and a child)