fear, threaten
慴 centers on a state of fear or being threatened, with the emotional response and the act of intimidation closely linked.
慴 combines the heart radical 忄 with 習, which likely provides the sound and may relate to repeated practice or flapping wings, but the exact historical development of the fear meaning is uncertain.
The heart 忄 beside 習 suggests a heart that repeatedly flutters like wings when afraid. Picture your heart pounding in fear as you are threatened.
For シュウ, imagine a threatening figure shouting 'Shoo!' to scare you away: 'Shoo!' -> シュウ, and your heart races with fear.