gyrfalcon (n.) Look up gyrfalcon at Dictionary.com
also gerfalcon, c.1200, from Old French girfauc "large northern falcon," probably from Frankish, from Proto-Germanic *ger (source of Old High German gir "vulture") + Latin falco "hawk" (see falcon). Folk etymology connects it with Latin gyrus (see gyre) in reference to "circling" in the air.