The word "clinch" has several meanings, depending on its context.
1) In boxing or other combat sports, a clinch is when two fighters are in close physical contact with each other, often holding onto one another's uniform or body. This can be used as an opportunity to rest or recover while also attempting to land strikes or take down the opponent.
2) In horse racing, a clinch is when horses come together and interfere with each other during a race, causing them to lose position or even fall.
3) Outside of sports contexts, "clinch" can refer to a final decision or conclusion reached after much deliberation. For example, "After hours of negotiations, the two parties finally clinched a deal."
4) In a more general sense, "clinch" can also mean to seal something with a finality, such as signing a contract or making an important decision that cannot be reversed.