stiffener

noun3

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 […] — 1856
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. — 2017