stiffener

noun

1. Anything added to something in order to stiffen it, such as a support beam, or starch for a collar.

   “[…] he wears a wisp of black silk round his neck, without any stiffener, as an apology for a neckerchief […]”

   “[…] each of these stiffener-columns must be designed to resist approximately 26 tons. Sometimes single angles are thus used as stiffeners […]”

   “The tee bar (b) is used as a stiffener to important bulkheads […]”

   “[…] with this arrangement the cylinders are cast separately from the saddle, and bolted to the frames on each side with a fabricated stiffener between the frames. This stiffener is carried up to form the saddle for the smokebox, and within it is fitted the exhaust pipes from the cylinders to the blast pipe.”

2. One of a series of angle bars, Z-bars, beams, rods, or other shapes, attached in order to provide them the necessary stiffness or rigidity.
3. (slang)An alcoholic drink taken to fortify oneself.

   “I believe the old man has taken himself off to the nearest bar for a stiffener.”