1590s, "one who observes flights of birds for the purpose of taking omens," from Latin auspex "interpreter of omens given by birds," from PIE *awi-spek- "observer of birds," from *awi- "bird" (see aviary) + *spek- "to see" (see scope (n.1)). Compare Greek oionos "bird of prey," also "bird of omen, omen," and ornis "bird," which also could mean "omen."
1590s, "one who observes flights of birds for the purpose of taking omens," from Latin auspex "interpreter of omens given by birds," from PIE *awi-spek- "observer of birds," from *awi- "bird" (see aviary) + *spek- "to see" (see scope (n.1)). Compare Greek oionos "bird of prey," also "bird of omen, omen," and ornis "bird," which also could mean "omen."