Refers to a person with outstanding talent or wisdom. Somewhat formal and literary; in everyday speech, 有能な人 or 才能のある人 are more common.
He is regarded as one of the greatest men of ability of our time.
Compound of 賢 (wise, clever) and 才 (talent, ability). The exact historical derivation is uncertain, but the combination directly conveys the meaning of a person with both wisdom and talent.