snow, (kokuji)
膤 is a Japanese kokuji centered on snow, likely created to refer to snow-related body parts or conditions, though its standalone meaning is simply snow.
膤 is a Japanese kokuji formed by combining the flesh radical ⺼ with 雪 (snow), likely to express a snow-related bodily concept. The exact historical development is uncertain.
The flesh radical ⺼ beside snow 雪 suggests snow in the body, like a snowman's flesh made of snow. Picture a snowman's body part labeled with this kanji.
For セツ, imagine a snowman's body part being surgically set: set -> セツ, and the snow flesh is carefully placed.