Foil

(foil.) [Fr. feuille, literally, a leaf. ] Among jewellers, a thin leaf of metal placed under gems and precious stones to increase their lustre and improve their color.-(Com.) Thin sheet-lead, used for the lining of tea chests.-[From O. Fr. re foulé, blunted.] (Fencing.) An elastic rod of steel, or a pointle sword, used to fence with by way of exercise. It generally has at the end a button or a leather-covered piece of cork, in order to prevent accidents.-(Arch.) In Gothic architecture, the span between the cusps of feathering:-otherwise termed Foiling. [s. 373]