to cut, injure, stab, stick on
劌 centers on causing harm with a sharp object: cutting, stabbing, or injuring. The sense of sticking on likely refers to piercing or impaling something.
劌 combines 歲 (likely a phonetic component) with 刂 (knife), suggesting a cutting or stabbing action. The exact historical development is uncertain.
The left side 歲 looks like a collection of sharp, jagged strokes, and the right side 刂 is a knife. Imagine using a knife to cut through a tangled, thorny mess, causing injury.
For ケイ, picture a sharp knife cutting into a piece of cake: cake -> ケイ, and the knife stabs into the soft cake.