be sad, grieve
慯 centers on emotional pain: being sad or grieving. It expresses a state of heartfelt sorrow.
慯 combines 忄 (heart) with a phonetic component that likely contributed the sound ショウ. The exact historical development of the right side is uncertain.
The heart radical 忄 on the left shows that this feeling comes from deep inside. The right side looks like a person hunched over under a heavy sun, grieving.
For ショウ, imagine a sad show where the actor grieves on stage: show -> ショウ, and the heart 忄 feels the sorrow.