stiffener

One who or that which stiffens.

In iron ship-building, one of a series of angle-bars, Z-bars, or other shapes, riveted to plating, particularly to the plating of bulkheads, to give them the necessary stiffness or rigidity. Stiffeners are called vertical stiffeners or horizontal stiffeners, according to the way they are arranged on the bulkhead.

One who, or that which, stiffens anything, as a piece of stiff cloth in a cravat.

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

Material used for stiffening something.