fumes
n. C / Un. strong-smelling gas or smoke that is often dangerous to breathe. You usually hear this word when people talk about cars, chemicals, or fire.
n. strong, unpleasant, and often noxious gas, smoke, or vapour. Frequently used in the plural to describe the exhaust from engines or the scent of volatile chemicals.
The garage was filled with exhaust fumes.
The workers had to wear protective masks to avoid inhaling the toxic fumes from the industrial paint.
As the fire spread through the laboratory, thick acrid fumes billowed from the broken windows, forcing the emergency crews to establish a wide safety perimeter.
Almost always used in the plural form ('fumes') when referring to gas or smoke; the singular is rare and usually refers to a specific emission source.
the car's fumethe car's fumesWhen referring to exhaust or strong smells, the word is almost exclusively used in the plural.