LATH (0. Eng. laett, Mid. Eng. lappe, a form possibly due to the Welsh llath; the word appears in many Teutonic languages, cf. Dutch lat, Ger. Latte, and has passed into Romanic, cf. Ital. latta, Fr. latte), a thin flat strip of wood or other material used in building to form a base or groundwork for plaster, or for tiles, slates or other covering for roofs. Such strips of wood are employed to form lattice-work, or for the bars of venetian blinds or shutters. A " lattice" (O. Fr. laths) is an interlaced structure of laths fastened together so as to form a screen with diamond-shaped or square interstices. Such a screen was used, as it still is in the East, as a shutter for a window admitting air rather than light; it was hence used of the window closed by such a screen. In modern usage the term is applied to a window with diamond-shaped panes set in lead-work. A window with a lattice painted red was formerly a common inn-sign (cf. Shakespeare, 2 Hen. IV. ii. 2. 86); frequently the window was dispensed with, and the sign remained painted on a board.