The phrase "becomes stale" refers to food or other items losing their freshness, flavor, and appeal over time. The antonyms for becomes stale are fresh, lively, invigorated, rejuvenated, restored, and renewed. When something is fresh, it is new and flavorful, and when something is lively, it is full of energy and vitality. Invigorated and rejuvenated describe items that have been renewed with new life or flavor. Restored describes something that has been brought back to its original state and renewed to its full potential. Finally, renewed describes items that have been refurbished or reinvigorated to become fresh and new again. All these antonyms indicate a renewed freshness or vitality, opposite from the dullness of something that becomes stale.