poorly balanced or matched in quantity or value or measure
source: WordNet 3.0
lacking the requisite qualities or resources to meet a task
Inadequate training. The staff was inadequate. She was unequal to the task.
source: WordNet 3.0
Not equal; not matched; not of the same size, length, breadth, quantity, strength, talents, acquirements, age, station, or the like; as, the fingers are of unequal length; peers and commoners are unequal in rank.