noun
1.
physical, mental, or legal power to perform
he has the ability to accomplish whatever he sets his mind to
Synonyms: adequacy, capability, capacity, competence, might, qualification, qualifiedness
Related Word: address, adroitness, cleverness, dexterity; aptitude, aptness, facility, knack
Idioms: what it takes
Contrasted words: impotence, inadequacy, incapability, incompetence
Antonyms: inability
2.
natural or acquired proficiency especially in a particular activity
he has unusual ability in planning and designing
Synonyms: command, expertise, expertism, expertness, knack, know-how, mastership, mastery, skill
Related Word: adroitness, deftness, efficiency, handiness, proficiency; ingenuity, resourcefulness; talent
Contrasted words: inadequacy, incompetence, ineffectualness, unfitness; fatuity, futility, inanity