底线 dǐxiàn HSK7 bottom line Definitions Defs Origin Strokes Stroke Words Sentences Sents Showing: under thread All meanings 8 dǐxiàn 8 bottom line 5baseline 1spy 1under thread 1 1 sentence for 底线 (dǐxiàn — under thread) 缝纫机的底线断了,需要重新安装。 féngrènjī de dǐxiàn duàn le, xūyào chóngxīn ānzhuāng. The bobbin thread of the sewing machine broke and needs to be reinstalled. Source: Dong Chinese Dictionary