1) Ensuring 
[metalworking] Clinching is a mechanical fastening method to join sheet metal without additional components, using special tools to plastically form a mechanical interlock between the sheets. It does not create heat. The tools consist typically of a punch and a die. There are two primary types of dies: solid `fixed cavity` dies, and dies wi...
• (p. pr. & vb. n.) of Clinch
The process of forming or bending a component lead following its insertion through a hole in a circuit board. The main purpose is to secure the part mechanically during the soldering process. 
When two boxers grapple with each other on the inside. Usually results in the ref breaking it up.