overflowing, billowing, wavy
灩 centers on water in a state of excess motion: overflowing, surging in large waves, or billowing restlessly.
灩 combines 氵 (water) with 豔, which likely contributes the sound and the idea of abundance or overflowing. The exact historical development is uncertain.
The water radical 氵 beside the dense, layered shape 豔 suggests water piling up and spilling over. Picture a container so full that waves surge and overflow.
For エン, imagine an enormous wave ending in a huge splash: the 'en' sound of 'end' cues エン as the water overflows.