What is "clinches"

Usage examples of "clinches".

After that he never let him rest, receiving punishment himself, but inflicting far more, smashing Sandel to the ropes, hooking and driving all manner of blows into him, tearing away from his clinches or punching him out of attempted clinches, and ever when Sandel would have fallen, catching him with one uplifting hand and with the other immediately smashing him into the ropes where he could not fall.

The Clinches were passing through the nanny choke-point of autumn: several new ones would be starting over the next couple of weeks.

Also, in the clinches King rested his weight on his opponent, and was loath to let go.