The Ancient Greek word for excellence is aretḗ (ἀρετή). It can also be translated as "fulfillment" or "virtue". In early Greek moral thought, aretḗ was something that people strived for throughout their lives. 

Aretḗ can refer to excellence in any kind, especially a person or thing's "full realization of potential or inherent function". It can also refer to excellence in "moral virtue". 

Aristotle referred to aretḗ as virtue, but the meaning of virtue in Aristotle's time was different than it is today.