Joist

·vt To fit or furnish with joists.

II. Joist ·noun 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, ·adj.