inefficient (adj.)

• artless
• careless
• inapt
• inattentive
• incapable
• incompetent
• ineffective
• ineffectual
• inefficacious
• inept
• inexpert
• inferior
• mediocre
• pedestrian
• poor
• slipshod
• slovenly
• thoughtless
• unable
• unendowed
• unfit
• unintelligent
• unprepared
• unqualified
• unskilled
• unskillful
• untalented
• untrained
• unworkmanlike