gyrfalcon (n.)

large falcon used in hawking, also gerfalcon, c. 1200, partly Englished from Old French girfauc "large northern falcon," probably from a Frankish compound with Latin falco "hawk" (see falcon) + first element meaning "vulture," from Proto-Germanic *ger (source of Old High German gir "vulture"). Folk etymology since the Middle Ages has connected it with Latin gyrus (see gyre (n.)) in reference to "circling" in the air.