Semen. The gooey, white liquid that shoots out of a penis during an ejaculation; it contains sperm cells that are necessary to make a baby, which can happen when semen ends up inside someone’s vagina. Most of the liquid in semen is made by the prostate. There are a lot of slang terms for semen, including cum/come, jizz/jism, seed, splooge, load, wad, nut, etc.