girdˈer noun

1. A large beam, simple or built up, of wood, iron or steel, to take a lateral stress, eg to support a floor, wall, or the roadway of a bridge
2. A strip of strengthening tissue (botany)

girdˈing noun

That which girds

girder bridge noun

A bridge whose load is sustained by girders resting on supports

gird oneself

1. To tuck up loose garments under the girdle (so as to be better able to run or act quickly)
2. To brace the mind for any trial or effort
3. See also loin