1. materials or devices used to make something rigid or less flexible
Usage: engineering; construction
2. structural elements added to strengthen or prevent buckling in beams, plates, or frameworks
Usage: technical; structural engineering

Examples

• The engineer added steel stiffeners to prevent the bridge deck from flexing.
• Collar stiffeners keep dress shirt collars crisp and properly shaped.
• The aircraft wing required additional stiffeners to handle the increased load.
• Fabric stiffeners are used in crafting to make materials hold their shape.
• The metal panel needed vertical stiffeners to prevent warping under pressure.
• Removable plastic stiffeners can be inserted into shirt collars before washing.