raise, lift up, tight-fisted
摳 centers on using the hand to lift or raise something, often with a sense of grasping tightly. The meaning 'tight-fisted' extends this to holding onto things in a stingy way.
摳 combines 扌 (hand) with 區, which likely contributes the sound. The exact historical development of the meaning 'tight-fisted' is uncertain, but it may derive from the idea of a hand grasping firmly.
The hand radical 扌 beside 區 suggests a hand lifting or raising something. Imagine a hand gripping tightly and pulling upward, like a stingy person clutching their money.
For コウ, picture a hand lifting a heavy box with a grunt: 'Koh!' The sound 'koh' cues コウ as the hand raises the load.