'Mēn hú lu' literally means 'stifled gourd'—a reference to the hollow, sealed shape of a dried bottle gourd (a type of squash), which makes no sound when shaken. By extension, it describes a person who is unusually quiet, reserved, or emotionally closed-off, giving little away in conversation or expression. The image evokes someone as impenetrable and silent as a sealed gourd: you can't tell what's inside just by looking or listening.

This idiom is commonly used in informal spoken Chinese, often with mild teasing or gentle exasperation—especially when someone refuses to share feelings, opinions, or information despite being asked. It carries no strong negative judgment but implies curiosity or mild frustration from others. While rooted in an agricultural object (gourds are plants), the term is categorized under 'Animals' in many pedagogical frameworks due to its frequent appearance alongside animal-based idioms in traditional Chinese figurative language and its use in character-driven storytelling.