This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The modern form combines 忄 (heart/mind) with 芒, but the original semantic and phonetic roles are unclear.
The heart radical 忄 beside 芒 (which resembles a busy, grassy shape) suggests a flustered or hurried state of mind, but the exact meaning is not well established.
For ボウ, imagine a bow (ボウ) tied around your heart, making you feel hurried and anxious: bow -> ボウ.