hold, gather with hand, choke
掐 centers on using the hand to grip or pinch tightly: holding something firmly, gathering with the fingers, or choking by constricting.
掐 combines 扌 (hand) with 臽, which likely contributes the sound and may relate to a pit or trap, suggesting a hand closing in or gripping. The exact historical development is uncertain.
The left side is a hand 扌, and the right side 臽 looks like a hand reaching into a trap. Picture your hand closing tightly around something, holding it firmly or choking it.
For コウ, imagine a hand gripping a collar tightly: the collar sound cues コウ, and the hand is choking or holding firmly.