The phrase "art in vain" refers to the concept of creating art without achieving its desired purpose or goal. The antonyms, or opposite meanings, of this phrase could include successful art, meaningful art, purposeful art, or impactful art. Successful art would suggest that the artwork has achieved its intended objective, while meaningful art would imply that the artwork conveys a message or emotion that resonates deeply with the viewer. Purposeful art would indicate that the artwork has been created with a specific intention in mind, while impactful art would suggest that the artwork has made a significant and lasting impression on its audience. Overall, these antonyms provide a roadmap for artists to create works that are not done in vain but instead have a purposeful, meaningful, and impactful impact on the world around them.