n.1 any of various protective head-coverings worn by soldiers, policemen, firemen, divers, motor cyclists, etc.
2 Bot. the arched upper part of the corolla in some flowers.
3 the shell of a gastropod mollusc of the genus Cassis, used in jewellery.
Derivatives:
helmeted adj.
Etymology: ME f. OF, dimin. of helme f. WG (as HELM(2))