The antonym for the word "art inefficient" is "efficient." This means that something is capable of achieving the desired results with the minimum amount of effort, time, or resources. When something is efficient, it is functioning as intended and producing the desired outcome effectively. It is important to strive for efficiency in all aspects of life, from work to personal activities. Improving efficiency can lead to greater productivity, better results, and increased satisfaction in one's achievements. In business, efficiency can be critical to profitability and success, while in personal life, it can help reduce stress and free up time for other activities.