"饭桶" (fàntǒng), which means "wooden rice bucket" literally, originally referred to a good appetite. Later, it's extended to describe a big eater who's good for nothing but eating rice. He/she's extremely useless.
In the ancient times, all buckets were hand-made of wood. It's such a handcraft that the artisan must make a bucket by assembling the wood piece by piece. As a result, the quality of the wooden buckets varied – the good-quality ones were watertight, while the poor-quality ones were not. As the defective cannot be used to fill with water, it's used to fill with rice. Later, the word "饭桶" was used as a derogatory term to describe a good-for-nothing.
1. rúguǒ nǐ bùnéng yǒu jiézhì de yǐnshí, què zài wǔyè de shíhou tōutōu liūjìn chúfáng chī bǐnggān, nàme nǐ jiùshì yígè fàntǒng.
If you cannot stick to your diet, but sneak down to the kitchen in the middle of the night for a biscuit, you're a waste of space.
2. qíshí, tā shì ge fàntǒng.
In fact, he is good for nothing.
The article is translated and editted by Chinlingo. Please indicate the source for any use, reproduction or transfer.