joist

noun

ˈjȯist 

: any of the small timbers or metal beams ranged parallel from wall to wall in a structure to support a floor or ceiling

Illustration of joist

• J joist

Examples of joist in a Sentence

Recent Examples on the Web

The kit comes with every part of the frame, from floor joists to top and bottom wall plates, studs, roof trusses, headers and sills for doors and windows, and columns to support the porch. — Caley Sturgill, Southern Living, 8 July 2026

When using 5/4 decking, the joists should not be spaced more than 16 inches apart. — Caitlin Sole, Better Homes & Gardens, 7 July 2026

But because that level rests on wooden floor joists, which bend a bit, the tiles might have cracked. — Dean Kaufman, Curbed, 30 June 2026

Rough carpenters must install floor joists with minimal or no crown. — Tim Carter, Hartford Courant, 6 June 2026

Word History

Etymology

Middle English giste, joiste, from Anglo-French giste, from Vulgar Latin *jacitum, from Latin jacēre to lie — more at adjacent

First Known Use

15th century, in the meaning defined above

Rhymes for joist

• foist
• hoist
• moist
• voiced
• invoiced
• rejoiced
• unvoiced

Kids Definition

joist

noun

ˈjȯist 

: a small beam laid crosswise to support a floor or ceiling