1 [singular]ability to do somethingthe fact that somebody/something is able to do somethingThe 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.
opposite
inability2 [countable, uncountable] a level of skill or intelligenceAlmost everyone has some musical ability.He was a man of extraordinary abilities.students of mixed abilitiesA woman of her ability will easily find a job.I try to do my job to the best of my ability(= as well as I can).