Middle English fusile, borrowed from Latin fūsilis "molten, liquified," from fūsus (past participle of fundere "to pour, shed, cast") + -ilis "subject to, susceptible to (the action of the verb)" (alteration of -ibilis, originally by haplology after verb stems ending in a labial consonant) — more at found entry 5, -able
Noun
borrowed from French (17th century), "steel for striking fire, flintlock firearm," going back to Old French foisil, focil "steel for striking fire," going back to Vulgar Latin *focīlis, from Latin focus "hearth" (Late Latin, "fire") + -īlis, suffix of appurtenance — more at focus entry 1
