The adjective efficient describes function and use with the least amount of waste and most economy.

Is efficiently an adjective or adverb?

The adverb efficiently has origins in the Latin word efficere, meaning "work out, accomplish." Efficiently can describe any action that's done without wasting time, effort, or materials — and still manages to produce the desired outcome.

Is effectively an adjective?

The adjective effective describes things that are adequate to accomplish a purpose, or that produce the intended or expected result. But effective isn't quite the same as effectual, efficacious, or efficient!