Early 17th century; earliest use found in Andrew Willet (d. 1621), Church of England clergyman and religious controversialist. From classical Latin genethlialogia art of casting nativities or horoscopes (Vitruvius) from Hellenistic Greek γενεθλιαλογία from ancient Greek γενέθλιος of or belonging to one's birth, of one's race or family + -λογία.