1. Failing to inform or clarify
   "an unenlightening comment"
   - unilluminating 
2. Not edifying
   - unedifying

Antonym: enlightening

• atonal
• atonalism
• atonalistic
• atonality
• atonally
• atone
• atonement
• atonia
• atonic
• atonicity
• atony
• atop
• atopic
• atopic allergy
• atopic dermatitis
• atopic eczema
• atopognosia
• atopognosis
• atopy
• atorvastatin
• atoxic
• ATP
• atrabilious
• choc
• choc-ice