a.

1. 不完美的；有缺點的；有瑕疵的
   imperfect products

   有瑕疵的產品

2. 不完整的；殘缺的；未完成的
   an imperfect knowledge of French

   對法語一知半解

3. 【語】未完成時的；未完成過去時的
4. 【音】不完全協和的

n.

1. 【語】未完成時（動詞）；未完成過去時（動詞）[the S][C]

adj.

1. faulty or incomplete.
2. Grammar  (of a tense) denoting a past action in progress but not completed at the time in question.
3. Music  (of a cadence) ending on the dominant chord.
4. Law  (of a gift, title, etc.) transferred without all the necessary conditions or requirements being met.