Dumbelina
A stupid girl, brainless, laughable, daft. A girl who acts in a stupid or unintellilgent manner.
Marcy is such a dumbelina.
Dumbelina
A total fuck up, who cannot express their true feelings as they are too incompetent to do so.
Josh was acting like a dumbelina when he fell and started crying but was unable to form a complete sentence to explain what had just occurred.