The antonyms for the term "most uneconomical" are "most economical", "cost-effective", "efficient", "practical", and "sensible". These terms refer to the opposite of being wasteful and expensive, indicating that something is efficient, useful, and intelligently planned. For instance, a car with fuel-efficient technology is cost-effective and practical, making it more useful than a car that consumes more fuel. Similarly, using energy-efficient appliances and making sustainable lifestyle choices can lead to economical and practical solutions for everyday life. By understanding the antonyms for the word "most uneconomical," individuals and companies can work towards more sustainable and cost-effective practices.