Definition of girder

• n. - One who girds; a satirist.
• n. - One who, or that which, girds.
• n. - 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.