Put me down this instant.

Dear Word Detective:  Passing a building site recently, I saw a foolhardy worker wandering across a girder quite a long way from the ground.  Because my mind works in a very odd fashion, I didn’t worry about his impending fall, but wondered about the word “girder.”  It is the sort of word that niggles away at the subconscious until it sounds ridiculous.  On inspecting my dictionary, there was no attempt at explaining its origins, although “gird” was the next word up.  I can’t see the connection. — David, North Yorkshire, England.

Well, let’s hope that the guy wandering around up there isn’t musing on the possible origins of “girder.”  Personally, I can’t even stand to look at those historical pictures of workers building skyscrapers in New York City.  But I’ve always felt that acrophobia (fear of heights) is the most sensible of the phobias.  Agoraphobia (fear of public places) and claustrophobia (fear of enclosed spaces) can often be overcome, and living in the country has lessened my arachnophobia (fear of spiders) to some degree.  But until someone teaches me how to fly by flapping my arms, acrophobia still makes perfect sense to me.

The connection between the steel “girders” that support buildings, bridges and the like and the verb “to gird” may not be immediately obvious, but it is fairly direct.  We inherited “gird” from Old English, where, in the form “gyrdan,” it meant “to put a belt around,” specifically to secure one’s garments in preparation for action, as before a battle, etc.  For much of its history in English, “gird” has been used in a figurative sense meaning “to prepare oneself,” as in the Biblical injunction “to gird one’s loins” (“He was already girding himself for his life’s work,” 1860).  “Gird” has also been used in a number of literal senses, from “to fasten a saddle to a horse” (using a strap called a “girth,” a noun we use today to mean “circumference” or “waistline”) to “encircle a town with a military force; to blockade.”

Given that the English suffix “er” attached to a verb usually designates a person or thing that performs the action of  the verb (a “driver” drives, etc.), you might expect a “girder” to be the guy who fastens your belt for you, or perhaps helps you put on your armor before battle.  But the sense of “gird” embedded in “girder” is a bit more general, that of “to fasten securely, to tie firmly,” which is exactly what a “girder” does in a building.  From its very earliest appearance in English in the 17th century, “girder” has meant “the main beam supporting a floor” or a supporting element that plays the equivalent role in a bridge.  The “girders” in a building tie the whole shebang together and form the strong skeleton supporting the floors, walls, etc., that make up the whole building.

By the way, “gird” has another relative in English, “girdle,” which springs from the same root and has a similar history.  The original sense of “girdle” as a noun was simply “belt,” often specifically one designed to support weapons such as a sword.  Today as a noun, “girdle” is used primarily to mean “elastic corset,” but as a verb it is a synonym of “gird,” and commonly used to mean “surround or bind” either literally or metaphorically (“The city is girdled by an intricate system of highways.”).