You searched for: “clinch
clench, clinch
clench (KLINCH) (verb)
To hold or to close tightly: Angelo started to clench his fists when he saw that the man was angry.

We could see Rudolph clench his teeth as he continued to look straight ahead.

clinch (KLINCH) (verb)
To finalize or to bring to an end: The judge’s comments appeared to clinch the argument between the lawyers.

Erika's superior work on this project should clinch her a promotion.

It's a cinch that when the debater is trying to clinch his arguments, he will clench his fists and pound on the table top.