The phrase "throw the sponge" means to surrender or give up. Antonyms for this phrase include persevering, persisting, fighting, enduring, and continuing. Essentially, any word that embodies resilience and perseverance is an antonym for "throw the sponge." These opposite words encourage one to keep going, even in the face of opposition, and to persevere through challenging circumstances. Overall, while "throwing the sponge" might seem like the easy way out, the antonyms suggest that there is value in enduring, persevering, and staying the course, no matter how hard it may be.