stormy, cloudy, misty, dim
曀 centers on obscured light and turbulent weather: a sky that is stormy, cloudy, misty, or dim. The common thread is reduced visibility and unsettled atmospheric conditions.
曀 combines 日 (sun) with 壹, which likely contributes the sound. The character expresses the idea of the sun being obscured by clouds or mist, leading to dim, stormy conditions.
The sun 日 is blocked by a dense, complex shape 壹, like thick storm clouds rolling in. When the sun is hidden, the sky turns cloudy, misty, and dim.
For エイ, imagine the dim, cloudy sky slowly brightening as the sun breaks through, like the letter 'A' emerging from the gloom: 'A' -> エイ.