B1
working or operating quickly and effectively in an organized way
Dictionary examples:
The efficient waiter served 100 tables without spilling a single drop! (0.0)
The efficient student finished a 10-page essay during a TV commercial break! (0.0)
My efficient friend cleaned the whole house in the time I brushed my teeth! (0.0)
The city's transportation system is one of the most efficient in Europe. (34.6)
We need someone really efficient who can organize the office and make it run smoothly. (51.0)