coitus /kō″itəs/ [L, coire, to come together] , intimacy-based physical interaction of any kind between two people, causing sexual excitation and/or orgasm in one or both partners. In the context of human reproduction, also called sexual intercourse, defined as a penis inserted into the vagina and ejaculation of semen containing sperm after sufficient sexual stimulation. Also called coition. See also copulation, sexual intercourse. −coital, adj.
