汗 ㄏㄢ ˋ hàn 牛 ㄋㄧㄡ ˊ niú 充 ㄔㄨㄥ chōng 栋 ㄉㄨㄥ ˋ dòng 汗 ㄏㄢ ˋ hàn 牛 ㄋㄧㄡ ˊ niú 充 ㄔㄨㄥ chōng 棟 ㄉㄨㄥ ˋ dòng lit. enough books to make a pack-ox sweat or to fill a house to the rafters (idiom); fig. many books