/-beə(r); -,bɛr/
adj
1 (of cloth, clothing,etc) worn thin; shabby （指织物、衣服等）磨薄的, 破旧的
*a threadbare carpet, coat 破烂的地毯、大衣.
2 (fig 比喻) too often used or too well known to be effective; hackneyed 因经常使用或尽人皆知而无效力的; 陈腐的
*a threadbare argument, joke, plot 陈旧的论点、笑话、情节.

adj
clothes, carpets etc that are threadbare are very thin and in bad condition because they have been used a lot
　a threadbare old sofa
threadbare excuse/argument/joke etc
an excuse etc that is no longer effective because it has been used too much