Spermatogenesis: The process of sperm formation. The term was created from the prefix "spermato-" (Greek sperma, the seed or germ) + "genesis" (the coming into being of something) = the coming into being of sperm. Spermatogenesis is in contrast to oogenesis, the process of egg (ovum) formation. SLIDESHOW Erectile Dysfunction (ED) Causes and Treatment See Slideshow From Men's Health Resources Have Blocked Hair Follicles? What Is Hidradenitis Suppurativa?Truth About Glasses and Contacts Featured Centers Good and Bad Foods for PsoriasisVideo: Getting Personal on Life With MS Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19