This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
慞 combines the heart radical 忄 with 章, which likely contributes the sound. The exact historical development is uncertain.
The heart radical 忄 beside 章 suggests a state of mind, but the specific meaning is unclear. Imagine a heart marked by a chapter of fear.
For ショウ, picture a show of fear: show -> ショウ, and the heart 忄 trembles at the performance.