Putting them together, 窝囊废 (wōnangfèi) literally describes a person who is “spineless/bottled-up trash”—someone whose incompetence and weakness make them fundamentally useless.
In Chinese culture, there's often a strong social expectation for individuals, particularly men, to be capable, resilient, and able to provide for and protect their family. A 窝囊废 is the antithesis of this ideal. They are seen as a burden, a source of shame, and a failure in their social and familial duties. To call someone a 窝囊废 is to attack their core value as a person. It implies they lack courage (勇气 - yǒngqì), ability (能力 - nénglì), and self-respect. Comparison to “Loser”: While an English speaker might call someone a “loser” after they lose a game or fail a test, the term can sometimes be used lightly or even playfully. 窝囊废 is never light or playful. It is a serious, character-destroying insult. It's less about a single event of losing and more about a permanent state of being pathetic and weak. It carries a much heavier weight of shame than “loser” and is closer in severity to calling someone “a pathetic good-for-nothing.”
This term is highly informal and aggressive. You will most often hear it in heated arguments, moments of extreme frustration, or in media to describe a particularly pathetic character.