vessel used hold grain offerings
璉 refers to a specific type of ritual vessel used for holding grain offerings in ancient ceremonies.
璉 combines 王 (jade/jewel) with 連, which likely contributes the sound. The character denotes a ritual vessel, possibly made of or decorated with jade.
The jewel radical 王 suggests a precious object, and the right side 連 (link/connect) hints at a vessel used to connect offerings to the divine. Picture a beautifully crafted jade vessel holding grain for a ceremony.
For レン, imagine a ceremonial vessel so precious it is kept in a special den: den -> レン, and the vessel holds sacred grain.