Definition from Wiktionary, the free dictionary
- Rhymes: -ɔɪst
joist (plural joists)
- 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.
piece of timber
to furnish with joists