casque: (15-16th century) any armor for the head; usually ornate without a visor
helmet: armor plate that protects the head
theravada: one of two great schools of Buddhist doctrine emphasizing personal salvation through your own efforts; a conservative form of Buddhism that adheres to Pali scriptures and the non-theistic ideal of self purification to nirvana; the dominant religion of Sri Lanka (Ceylon) and Myanmar (Burma) and Thailand and Laos and Cambodia