[ joist ]
/ dʒɔɪst /


any of a number of small, parallel beams of timber, steel, reinforced concrete, etc., for supporting floors, ceilings, or the like.

verb (used with object)

to furnish with or fix on joists.


Origin of joist

1325–75; Middle English giste < Old French < Latin *jacitum support, noun use of neuter of Latin jacitus (past participle of jacēre to lie), equivalent to jaci- variant stem + -tus past participle suffix

Related forms

joist·less, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for joist

British Dictionary definitions for joist


/ (dʒɔɪst) /


a beam made of timber, steel, or reinforced concrete, used in the construction of floors, roofs, etcSee also rolled-steel joist


(tr) to construct (a floor, roof, etc) with joists

Word Origin for joist

C14: from Old French giste beam supporting a bridge, from Vulgar Latin jacitum (unattested) support, from jacēre to lie
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012