imperfection (n.)

• absence
• arrears
• baseness
• beggary
• blemish
• bug
• catch
• crack
• damage
• decline
• defalcation
• default
• defect
• defection
• defectiveness
• deficiency
• deficit
• delinquency
• demerit
• deprivation
• destitution
• drawback
• drought
• error
• failing
• failure
• fallibility
• famine
• fault
• fewness
• flaw
• foible
• frailty
• hole
• impoverishment
• inadequacy
• incompetence
• incompleteness
• inferiority
• infirmity
• insufficiency
• kink
• lack
• littleness
• maladroitness
• meanness
• mediocrity
• need
• omission
• peccadillo
• pettiness
• problem
• rift
• shabbiness
• shortage
• shortcoming
• shortfall
• sin
• slump
• smallness
• snag
• starvation
• subnormality
• taint
• triviality
• underage
• unskillfulness
• vice
• vulgarity
• want
• weakness