1. Air pollution by a mixture of smoke and fog
   - smog

See also: smoggy

Type of: air pollution

• 3TC
• 4
• 4-dimensional
• 4-hitter
• 4-membered
• 40
• 400
• 400th
• 401-k
• 401-k plan
• 40th
• 41
• 41st
• 42
• 42nd
• 43
• 43rd
• 44
• 440 yards
• 44th
• 45
• 45th
• 46
• 46th
• 47