leaf
A hinged part; one of the movable members of a door or shutter. The term valve is sometimes used to describe one of the leaves of a French door, double door, etc. 2. One of the two halves of a cavity wall. 3. In the realm of architectural ornamentation, the term leaf is used to describe a decorative motif that represents a leaf; quite often applied to molding. 4. One of the vertical component parts of a built-up member; consisting generally of one or more web plates with top and bottom angles, or one rolled channel. Usually two in number and sometimes three. (Phillips, 1994)