headgear
any covering for the head; element of clothing which is worn on one's head
beanie
small round cap, often colorful
turban
headwear
corolla
wreath or garland for the head in Roman times
hat
shaped head covering, having a brim and a crown, or one of these
helmet
covering worn to protect the head, either historical or modern
mitre
liturgical headdresses worn by Christian bishops and abbots
circlet
diadem