Joist n. Arch. A piece of timber laid horizontally, or nearly so, to which the planks of the floor, or the laths or furring strips of a ceiling, are nailed; -- called, according to its position or use, binding joist, bridging joist, ceiling joist, trimming joist, etc. See Illust. of Double-framed floor, under Double, a.
Bind·ing a. That binds; obligatory.
Binding beam Arch., the main timber in double flooring.
Binding joist Arch., the secondary timber in double-framed flooring.
Syn: -- Obligatory; restraining; restrictive; stringent; astringent; costive; styptic.