brave, cautious, sad
慬 centers on a mix of emotional states that involve inner strength and restraint: being brave yet cautious, or feeling sadness that is held in check.
慬 combines the heart radical 忄 with 堇, which likely contributes a sound element. The exact historical development of the meaning is uncertain, but the character appears to express emotional states related to restraint or inner conflict.
The heart 忄 beside 堇 suggests a heart that is both brave and careful, like someone who faces hardship with controlled emotion. The sadness comes from holding back.
For キン, imagine a brave but cautious king (キン) whose heart is heavy with sadness: king -> キン, and his heart 忄 holds all three feelings.