long for, hungry
惄 centers on a deep, aching desire or need: longing for something absent, or feeling the emptiness of hunger.
惄 combines 叔 (which may have contributed a sound element) with 心 (heart/mind), suggesting a heart-centered state of yearning or hunger. The exact historical development is uncertain.
The top part 叔 looks like a hand reaching for something, and the bottom 心 is the heart. Picture a heart reaching out, aching with longing or hunger.
For デキ, imagine a person so hungry they dream of a deck of food cards: deck -> デキ, and their heart aches with longing.