Related Clues:

• Smoke or fog
• Jet trail
• Visible air
• Word with "lock" or "barrier"
• Kind of trail
• Clouds, e.g
• Fog or steam
• Mist or fog
• Steam, e.g
• Word before trail or lock
• Contrail, e.g
• Fog or mist
• Boiling byproduct
• Boiling evidence
• E-cigarette output