Mid 19th century; earliest use found in Thomas De Quincey (1785–1859), essayist. From Hellenistic Greek ὀρνιθοσκοπία divination from birds from ancient Greek ὀρνιθοσκόπος observing (and divining by) birds, auguring (from ὀρνιθο- + -σκόπος: see -scope) + -ία; compare -scopy. Compare French ornithoscopie.