Used as a verb in a sexual context: To expel a thick, white, gooey fluid called semen from the hole at the tip of a man's penis. To cum, to spooge, to bust a nut, etc. When used as a noun, ejaculate can also refer to said thick, white, gooey fluid. The aftermath of an ejaculation is sometimes referred to as an Explosion at the Yogurt Factory.
After she had made Peter ejaculate, Jenna's face looked like she had been in an explosion at the yogurt factory.