subdue, destroy, overcome
尅 centers on forceful overcoming: subduing, destroying, or defeating an opponent or obstacle.
尅 is a variant form of 剋, combining 克 (overcome) with 寸 (hand/action), suggesting the act of subduing. The exact historical development is uncertain.
The outer shape 克 suggests overcoming, and the inner 寸 adds a hand taking action. Together they show a hand forcefully subduing something.
For コク, imagine a cocky opponent being subdued: cock -> コク, and the hand inside 尅 overcomes them.