- exhaust (v.)
- 1530s, "to draw off or out, to use up completely," from L. exhaustus, pp. of exhaurire "draw off, take away, use up," from ex- "off" + haurire "to draw up" (as water), from PIE *aus- "to draw water." Noun sense of "waste gas" (1848) was originally from steam engines. Related: Exhausting.