Here are some possible interpretations and similar idioms:
* "Limp as a rag": This idiom means very weak, tired, or lacking in energy. It implies something is so exhausted it has lost its firmness and strength, like a wet rag.
* "Limp as a dishcloth": Similar to "limp as a rag," this idiom also suggests something is completely lacking in energy and strength.
* "Limp as a noodle": This idiom is similar to the previous two, but emphasizes the lack of stiffness and firmness in something, like a soft noodle.
If you heard this phrase, it might be a regional saying or a playful expression used in a specific context. However, it is not a standard idiom in English.