to close or hold something very tightly, often in a determined or angry way

The old man clenched his fist and waved it angrily at us. 那老头紧握着拳头，气哼哼地向我们挥舞着。

With a knife clenched in/between his teeth, he climbed up the tree to cut some coconuts. 他嘴里紧咬着一把刀，爬上树去割椰子。

"Get out of here," she said through clenched teeth. “滚出去，”她咬牙切齿地说。