Merriam-Webster Collegiate Dictionary - fusil

 I. adjective  or ~e  Etymology: Middle English, from Latin ~is, from fundere  Date: 14th century  1. archaic  a. made by melting and pouring into forms ; cast  b. liquefied by heat  2. archaic fusible  II. noun  Etymology: French, literally, steel for striking fire, from Old French foisil, from Vulgar Latin *focilis, from Late Latin focus fire — more at fuel  Date: 1680 a light flintlock musket