: a viscid whitish fluid of the male reproductive tract consisting of spermatozoa suspended in secretions of accessory glands (as of the prostate and Cowper's glands)
Whitish viscous fluid emitted from the male reproductive tract that contains sperm and liquids (seminal plasma) that help keep them viable. Sperm cells, produced by the testes in humans, represent 2–5% of semen volume; fluids from tubules, glands, and storage areas of the reproductive system bathe them as they travel down, nourishing them, keeping them motile, or participating in certain chemical reactions. During ejaculation, liquids from the prostate gland and seminal vesicles dilute the sperm and provide a suitable, slightly alkaline environment. An average ejaculation of a human male expels 0.1–0.3 cu inches (2–5 ml), containing 200–300 million sperm.