- a large beam, as of steel, reinforced concrete, or timber, for supporting masonry, joists, purlins, etc.
- a principal beam of wood, steel, etc., supporting the ends of joists.
Origin of girder
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for girder
Not even a girder that could be unfastened in time to brace the last door.Under Arctic Ice
Every interior floor and girder must have been treated with the gas.
This is the simplest form for metal bridge truss, or girder.Carpentry for Boys
J. S. Zerbe
The practice is to give these girder boxes a camber of ½-in.
The centering and the beam and girder forms were supported by 6×6-in.
- a large beam, esp one made of steel, used in the construction of bridges, buildings, etc
- botany the structure composed of tissue providing mechanical support for a stem or leaf
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
Word Origin and History for girder
"main supporting beam that carries flooring," 1610s, agent noun from gird, on notion of something that "holds up" something else. Used of iron bridge supports from 1853.
Online Etymology Dictionary, © 2010 Douglas Harper