grieve over, be disappointed
惆 centers on a heavy emotional state of sorrow and letdown: grieving over a loss or being deeply disappointed when expectations are not met.
惆 combines the heart radical 忄 with 周, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with emotional distress.
The heart radical 忄 beside 周 suggests a heart surrounded by sorrow, like grief closing in from all sides.
For チュウ, imagine chewing over a disappointment: chew -> チュウ, and your heart grieves as you dwell on it.