Meaning of duǎn:
短
short; brief; to lack; fault
Tā de tóufǎ hěn duǎn.
他的头发很短。
His hair is very short.
Tā de yǎnjiǎng fēicháng duǎn.
他的演讲非常短。
His speech was very brief.
Tā de yǎnjiǎng yǒuxiē bùzú, shì yīnwèi tā de zhǔnbèi shíjiān tài duǎn.
他的演讲有些不足,是因为他的准备时间太短。
His speech was somewhat inadequate because his preparation time was too short.
Tā de jìhuà yǒu yīgè xiǎo duǎn.
他的计划有一个小短。
His plan has a small fault.
weak point
Tā de nàixīn shì tā de yī gè duǎn bǎn.
他的耐心是他的一个短板。
His patience is his weak point.