(1) A downwards projecting shield protecting against entry of wind and rain. Also known as a PETTICOAT. (2) (of cap) A SKIRT protecting the curb below a CAP in a SMOCK or TOWER MILL. (3) (of postmill) A SKIRT keeping the weather out of the top of the round-house, usually a downward extension of the weatherboarding. (4) (of millstone) The outer third of the grinding surface of a millstone. (5) The outer edge of a millstone. Also known as the HEM.