General:
* Emissons: This is a more formal word for the gases released by a combustion engine.
* Fumes: This word is often used for smoke or vapor that is harmful or unpleasant.
* Waste: This is a broad term that can refer to any unwanted material, including exhaust.
* Discharge: This is a more formal word that can be used to refer to the release of any substance, including exhaust.
Specific:
* Smoke: For exhaust from a vehicle or other combustion engine.
* Vapor: For exhaust from a machine or chemical process.
* Gases: For exhaust from a variety of sources, including industrial processes.
* Effluent: For wastewater or other liquid waste.
Figurative:
* Deplete: This word can be used figuratively to describe the process of using up energy or resources.
* Tire: This word can be used figuratively to describe the feeling of being worn out or exhausted.
Please provide more context about how you are using the word "exhaust" so I can give you a more specific suggestion.