sallet

n. [ F. salade, Sp. celada, or It. celata, fr. L. (cassis) caelata, fr. caelare, caelatum, to engrave in relief. So called from the figures engraved upon it. ] A light kind of helmet, with or without a visor, introduced during the 15th century. [ Written also salade. ] [ 1913 Webster ]

Then he must have a sallet wherewith his head may be saved. Latimer. [ 1913 Webster ]