Girder

n.	1.	One who girds; a satirist.
	1.	One who, or that which, girds.
	2.	(Arch. & Engin.) A main beam; a stright, horizontal beam to span an opening or carry weight, such as ends of floor beams, etc.; hence, a framed or built-up member discharging the same office, technically called a compound girder. See Illusts. of Frame, and Doubleframed floor, under Double. Bowstring girder etc. See under Bowstring, Box, etc. Girder bridge See under Bridge. Lattice girder a girder consisting of longitudinal bars united by diagonal crossing bars. Half-lattice girder a girder consisting of horizontal upper and lower bars connected by a series of diagonal bars sloping alternately in opposite directions so as to divide the space between the bars into a series of triangles. Sandwich girder a girder consisting of two parallel wooden beams, between which is an iron plate, the whole clamped together by iron bolts. - Knight.

Noun

1.

girder - a beam made usually of steel; a main support in a structure

beam, I-beam