Answer: efficient

AnswerCrossword Clue
EFFICIENTWorking well.
EFFICIENTWorking well
EFFICIENTBusiness-like
efficient(esp. of a system or machine) Achieving maximum productivity with minimum wasted effort or expense
efficientPreventing the wasteful use of a particular resource
efficienta trained soldier, esp one volunteering for service
efficient(of a person) Working in a well-organized and competent way