leftovers
餕 centers on food that remains after a meal: leftovers. It refers to what is uneaten and set aside.
餕 combines the food radical 飠 with 夋, which likely contributes the sound. The character is associated with leftover food, but the exact historical development of the right component is uncertain.
The food radical 飠 on the left hints at a meal, and the right side 夋 looks like a person walking away from the table. Imagine someone leaving food behind: those are the leftovers.
For シュン, picture a chef shunning the leftovers: shun -> シュン, and the uneaten food is pushed aside.