Origin of gulesMiddle English goules from OFr, gules, red-dyed ermine, origin, originally plural of goule, the mouth from Classical Latin gula, throat: see gullet
Origin of gulesMiddle English goules from Old French red fur neckpiece pl. of gole throat from Latin gula
From Old French geule (“animal’s mouth, throat”) via Middle French geules. Compare with French gueules and Spanish gules.