raw meat for sacrifice
脤 centers on raw meat used in ritual offerings. Its meaning is narrow and specific to sacrificial contexts.
脤 combines the flesh radical ⺼ with 辰, which likely contributes the sound. The character is associated with sacrificial meat, but the exact historical development is uncertain.
The flesh radical ⺼ beside 辰 suggests meat prepared for a ritual. Picture a piece of raw meat offered on an altar during a ceremony.
For シン, imagine a shin bone of a sacrificial animal being used in the ritual: shin -> シン, and the meat is offered raw.