The quality of being inefficient; lack of power or energy sufficient for the desired effect; inefficacy; incapacity; as, he was discharged from his position for inefficiency.

unskillfulness resulting from a lack of efficiency

Some observers feel that financial markets are "efficient" to the point that the prices of investments generally reflect their value at all times. This is plain nonsense. While it's probably true that gaining exceptional returns on a consistent basis through investing in a portfolio of large, well-researched stocks is going to be difficult--and increasingly so in an ever-more global world--there are plenty of "pockets of inefficiency" around the world. These pockets are where value is to be found.

A level of production which is less than that accomplished under normal work ing conditions. [D05001] PDG

In terms of production, the condition where less than the maximum output is produced with given resources and technology. Inefficiency implies the possibility of gains in one area without losses in another.