To bend something

• To bend or move a joint
• To tighten or contract a muscle, often for display

To boast or brag

• To flaunt superiority, possessions, or achievements
• To show off

The act of flexing muscles

• A muscular pose
• Muscle tightening for display

A boast or showy display

• Something considered impressive or flashy
• An instance of showing off

A flexible insulated electrical cord or cable

• Chiefly British usage

Flexible ductwork of plastic over a wire coil

• Used for air distribution