Related Clues:

• Past question posed in Old English is unclear
• Murky old resentment apt originally for India
• Made uncertain
• Tough to see through
• (Of a liquid) not clear
• Opposite of ''transparent''
• Obscure work — a strange hesitation to avoid it
• Inside shop a queue's becoming dense
• Obscure old film on teeth student ignored
• Impervious to sight
• Impenetrable work leads to awkward questions, upsetting editor
• Ring Panama and Quebec as it's not clear
• Murky or nebulous
• Within country's borders it's somehow vulgar and gloomy
• Impenetrable to light