copulation
n. sexual intercourse: coitus. Copulation usually includes mounting, intromission (insertion of the penis into the vagina), and ejaculation. In some species (e.g., rats), several intromissions are necessary prior to ejaculation, and a female must receive several intromissions in order for ova to be implanted in the uterus. In other species, copulation is necessary to induce ovulation. In many socially monogamous species, such as human beings, copulation can occur irrespective of the stage of the female’s ovulatory cycle.