sexual intercourse (also intercourse)

insertion of a man's penis into a woman's vagina, usu leading to the ejaculation of semen; copulation 性交; 交媾.

sewing-machine, sewn, sex, sex act, sex appeal, sex life, sex-, sex-starved, sexagenarian, sexily, sexiness, sexism, sexist, sexless, sexologist, sexology, sextant, sextet (also sextette), sexton, sexual, sexuality, sexually, sexy, SF, sgd, Sgt, sh, shabbily, shabbiness, shabby, shack, shackle, shad, shade, shadily, shadiness, shading, shadow, shadow-box, shadow-boxing,