untalented (adj.)

• amateurish
• brainless
• foolish
• headless
• ignorant
• incapable
• incompetent
• ineffective
• inefficient
• inept
• inferior
• insensate
• irrational
• mindless
• reasonless
• semiskilled
• senseless
• unable
• unendowed
• unfinished
• unfit
• uninitiated
• unintelligent
• unpolished
• unprepared
• unprofessional
• unqualified
• unreasoning
• unschooled
• unskilled
• untaught
• unthinking
• untrained
• untutored
• unwise
• witless