a.

1. 能，可，会[F][+to-v]
   I am afraid I won't be able to visit you on Saturday.

   恐怕我无法在星期六来拜访您了。

2. 有能力的；能干的
   He is an able lawyer.

   他是一位能干的律师。

adj.

1. having the power, skill, or means to do something.
2. having considerable proficiency or intelligence.