Meaning : Being effective without wasting time or effort or expense.
Example :
An efficient production manager.
Efficient engines save gas.
Not producing desired results. Wasteful.
An inefficient campaign against drugs.Meaning : Able to accomplish a purpose. Functioning effectively.
Example :
People who will do nothing unless they get something out of it for themselves are often highly effective persons....
Effective personnel.
An efficient secretary.
The efficient cause of the revolution.
Synonyms : effective