The word "most eradicative" means having the ability to eliminate or eradicate to the highest degree. Its antonyms, or opposite words, would be those that suggest minimal or insufficient eradication. Some possible antonyms for "most eradicative" might include terms like "ineffective," "inefficient," "inept," "inadequate," or "unsatisfactory." These words all suggest an inability to successfully eliminate or eradicate something. Other antonyms might include words like "constructive," "adaptive," "mitigating," or "ameliorative," which suggest approaches focused on creating positive change instead of simply getting rid of something. No matter which antonyms are used, they all imply a different approach or level of efficacy in terms of eliminating something unwanted or harmful.