From the Oxford Learner's Dictionary: ability to do something the fact that somebody/something is able to do something The system has the ability to run more than one program at the same time. Everyone has the right to good medical care regardless of their ability to pay. A gentle form of exercise will increase your ability to relax. capability (to do something/of doing something) the ability or qualities necessary to do something Animals in the zoo have lost the capability to catch/of catching food for themselves. Age affects the range of a person's capabilities.