girder
n. countable C1 Advanced US //ˈɡɝdɝ// UK //ɡˈɜːdɐ// gird·er
n. a very strong, heavy beam used to support the structure of a building or bridge. It is usually made of steel and helps hold up the weight of the whole project.
n. a large, heavy beam or structural member used to support a bridge, roof, or other heavy construction. Typically fabricated from steel or reinforced concrete to provide high tensile and compressive strength.
The workers are lifting a heavy steel girder into place.
The bridge collapsed because one of the main girders had rusted through over several decades of neglect.
Modern skyscrapers rely on a complex network of steel girders and columns to distribute the immense weight of the upper floors across the foundation.
From gird + -er.