fumes

English Thesaurus

1. gases ejected from an engine as waste products (noun.substance)

hypernym	:	waste, waste material, waste matter, waste product,
definition	:	any materials unused and rejected as worthless or unwanted (noun.substance)

hypernym	:	gas,
definition	:	a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely (noun.substance)