transitive verb

1. to draw off or let out completely (air, gas, etc.), as from a container
2. to use up; expend completely to exhaust one's resources
3. 1. to empty completely; draw off the contents of; drain to exhaust a well
   2. to create a vacuum in
4. to drain of power, resources, etc. war exhausted the nation
5. to tire out; make very weary; weaken
6. to deal with, study, or develop completely and thoroughly to exhaust a subject

Etymology: < L exhaustus, pp. of exhaurire, to draw out, exhaust < ex-, out + haurire, to draw, drain < IE base *aus- > ON ausa

intransitive verb

noun

1. 1. the withdrawing of air, gas, etc. from a container or enclosure, as by means of a fan or pump
   2. an apparatus for doing this, as in getting rid of fumes, dust, stale air, etc.
2. 1. the discharge or release of used steam, gas, etc. from a steam or gas turbine or from the cylinders of an engine at the end of every working stroke of the pistons
   2. the system of pipes, including mufflers, catalytic converters, etc. through which such steam, gas, etc. is released
3. something given off or let out, as fumes from a gasoline engine