Related Clues:

• Stink
• Carbon monoxide's lack
• Lead for a Lab
• Whiff
• Fertilizer source
• It may be left in a locker
• Garlic, for one
• Pool problem
• Sure target
• Pervasive quality
• Fungus byproduct
• Something the nose knows
• Unpleasant aura
• Radon lacks it
• Nostril wrinkler