1570s, "emit semen," from Latin eiaculatus, past participle of eiaculari "to throw out, shoot out," from ex- "out" (see ex-) + iaculari "to throw, hurl, cast, dart," from iaculum "javelin, dart," from iacere "to throw" (see jet (v.)). Only other surviving sense is "exclaim suddenly" (1660s). Related: Ejaculated; ejaculating.
ejaculate e·jac·u·late (ĭ-jāk'yə-lāt')
v. e·jac·u·lat·ed, e·jac·u·lat·ing, e·jac·u·lates
To eject or discharge abruptly, especially to discharge semen in orgasm. n. (ĭ-jāk'yə-lĭt)
Semen ejaculated in orgasm.