Efficiency (noun)

1. The ability to do something or produce something without wasting materials, time, or energy.
2. The ratio of the useful work performed by a machine or in a process to the total energy supplied to it.

Origin:

From middle english efficient, from latin efficient-, from efficiens, present participle of efficere ("to accomplish, make, do"), from ex- ("out") + faciō ("do").

Examples:

1. He is known for his efficiency.
2. The company's efficiency improved after the new management took over.
3. The new machine has a high efficiency.
4. The efficiency of the process was measured.
5. He was praised for his efficiency in completing the task.