This word means "having adequate capacity to do, make, or receive an action": "Larry is a capable player." "This problem is capable of solution." A common error arises from using able for capable in one of these senses: "This law is capable (not able) of being enacted." One should say "I am able to solve this problem" and "I am capable of solving this problem."
Dictionary of problem words and expressions. Harry Shaw. 1975.