If "lazy" means "unwilling to work or exert oneself," some antonyms are:
* Diligent: showing care and conscientiousness in one's work or duties.
* Industrious: hardworking and diligent.
* Hardworking: putting in a lot of effort and work.
* Energetic: having or showing great energy and enthusiasm.
* Active: characterized by action or movement.
If "lazy" means "slow and sluggish," some antonyms are:
* Energetic: having or showing great energy and enthusiasm.
* Vigorous: strong, healthy, and full of energy.
* Spry: lively and active.
* Nimble: quick and light in movement.
If "lazy" means "lacking in ambition or drive," some antonyms are:
* Ambitious: having or showing a strong desire and determination to succeed.
* Driven: having a strong sense of purpose and determination.
* Motivated: having or showing a strong reason for doing something.
The best antonym for "lazy" will depend on the specific situation and the intended meaning.