This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
庿 is a variant or simplified form of 廟, which originally depicted a building (广) for ancestral rites. The inner component 苗 may be a phonetic or simplified replacement, but the exact historical development is uncertain.
The outer 广 suggests a building, and the inner 苗 (seedling) might hint at a place where ancestral spirits are nurtured. Imagine a quiet shrine building where seedlings of memory are kept.
For ビョウ, picture a small shrine building (广) where a seedling (苗) grows, and a visitor says 'byou' as a soft prayer: byou -> ビョウ.