Source : WordNet®

coitus
     n : 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 [syn: {sexual
         intercourse}, {intercourse}, {sex act}, {copulation}, {coition},
          {sexual congress}, {congress}, {sexual relation}, {relation},
          {carnal knowledge}]