The Collaborative International Dictionary of English v.0.48:

Exhaust \Ex*haust"\, a. [L. exhaustus, p. p.]
   1. Drained; exhausted; having expended or lost its energy.
      [1913 Webster]

   2. Pertaining to steam, air, gas, etc., that is released from
      the cylinder of an engine after having preformed its work.
      [1913 Webster]

   Exhaust draught, a forced draught produced by drawing air
      through a place, as through a furnace, instead of blowing
      it through.

   Exhaust fan, a fan blower so arranged as to produce an
      exhaust draught, or to draw air or gas out of a place, as
      out of a room in ventilating it.

   Exhaust nozzle, Exhaust orifice (Steam Engine), the blast
      orifice or nozzle.

   Exhaust pipe (Steam Engine), the pipe that conveys exhaust
      steam from the cylinder to the atmosphere or to the
      condenser.

   Exhaust port (Steam Engine), the opening, in the cylinder
      or valve, by which the exhaust steam escapes.

   Exhaust purifier (Milling), a machine for sorting grains,
      or purifying middlings by an exhaust draught. --Knight.

   Exhaust steam (Steam Engine), steam which is allowed to
      escape from the cylinder after having been employed to
      produce motion of the piston.

   Exhaust valve (Steam Engine), a valve that lets exhaust
      steam escape out of a cylinder.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Exhaust \Ex*haust"\, v. t. [imp. & p. p. Exhausted; p. pr. &
   vb. n. Exhausting.] [L. exhaustus, p. p. of exhaurire; ex
   out + haurire, haustum, to draw, esp. water; perhaps akin to
   Icel. asua to sprinkle, pump.]
   1. To draw or let out wholly; to drain off completely; as, to
      exhaust the water of a well; the moisture of the earth is
      exhausted by evaporation.
      [1913 Webster]

   2. To empty by drawing or letting out the contents; as, to
      exhaust a well, or a treasury.
      [1913 Webster]

   3. To drain, metaphorically; to use or expend wholly, or till
      the supply comes to an end; to deprive wholly of strength;
      to use up; to weary or tire out; to wear out; as, to
      exhaust one's strength, patience, or resources.
      [1913 Webster]

            A decrepit, exhausted old man at fifty-five.
                                                  --Motley.
      [1913 Webster]

   4. To bring out or develop completely; to discuss thoroughly;
      as, to exhaust a subject.
      [1913 Webster]

   5. (Chem.) To subject to the action of various solvents in
      order to remove all soluble substances or extractives; as,
      to exhaust a drug successively with water, alcohol, and
      ether.
      [1913 Webster]

   Exhausted receiver. (Physics) See under Receiver.

   Syn: To spend; consume; tire out; weary.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Exhaust \Ex*haust"\, n. (Steam Engine)
   1. The steam let out of a cylinder after it has done its work
      there.
      [1913 Webster]

   2. The foul air let out of a room through a register or pipe
      provided for the purpose.
      [1913 Webster]

WordNet (r) 3.0 (2006):

exhaust
    n 1: gases ejected from an engine as waste products [syn:
         exhaust, exhaust fumes, fumes]
    2: system consisting of the parts of an engine through which
       burned gases or steam are discharged [syn: exhaust,
       exhaust system]
    v 1: wear out completely; "This kind of work exhausts me"; "I'm
         beat"; "He was all washed up after the exam" [syn:
         exhaust, wash up, beat, tucker, tucker out]
    2: use up (resources or materials); "this car consumes a lot of
       gas"; "We exhausted our savings"; "They run through 20
       bottles of wine a week" [syn: consume, eat up, use up,
       eat, deplete, exhaust, run through, wipe out]
    3: deplete; "exhaust one's savings"; "We quickly played out our
       strength" [syn: run down, exhaust, play out, sap,
       tire]
    4: use up the whole supply of; "We have exhausted the food
       supplies"
    5: eliminate (a substance); "combustion products are exhausted
       in the engine"; "the plant releases a gas" [syn: exhaust,
       discharge, expel, eject, release]

Moby Thesaurus II by Grady Ward, 1.0:

352 Moby Thesaurus words for "exhaust":
   abate, ablate, absorb, assimilate, attenuate, avenue, backwash,
   bankrupt, beat, blackdamp, bleed, bleed white, blow, blow out,
   blowhole, blunt, breathe, breathe hard, breathe in, breathe out,
   broach, burden, burn out, burn up, carry too far, cast forth,
   castrate, channel, charge, chokedamp, chute, clean out, clear,
   clear away, clear off, clear out, clear the decks, coal gas,
   condensation trail, consume, contrail, cough, cramp, cripple,
   crush one, damp, dampen, deaden, debilitate, debouch, decant,
   defecate, defluxion, demasculinize, denude, deplete, deplume,
   desex, desexualize, despoil, devitalize, digest, disable,
   discharge, disembogue, disgorge, displume, dissipate, divest,
   do in, do up, door, draft, draft off, drain, drain of resources,
   drain off, drain out, drainage, draw, draw from, draw off, dry,
   dull, eat, eat up, effeminize, effluence, effluent, effluvium,
   efflux, effluxion, effusion, egress, ejaculate, eliminate,
   emanation, emasculate, emission, emit, empty, empty out, emunctory,
   enervate, enfeeble, erode, eruct, erupt, escape, estuary, etiolate,
   evacuate, eviscerate, exaggerate, exhalation, exhale, exhaust gas,
   exit, expel, expend, expire, extenuate, extravasate, fag, fag out,
   fatigue, find vent, finish, finish off, firedamp, flag, flay,
   fleece, floodgate, flow, flow out, flowoff, flume, frazzle,
   fritter away, fuel, fume, fumes, gas, gasp, give off, give out,
   give vent to, go overboard, go to extremes, go too far, gobble,
   gobble up, gruel, gulp, gush, gush out, hack, harass, haunt,
   haunt the memory, hiccup, huff, impoverish, ingest, inhale,
   inspire, issue, jade, jet, jet propulsion, knock out, knock up,
   know no bounds, lay low, let, let blood, let out, liquid oxygen,
   loophole, lose, malaria, mephitis, milk, mitigate, obsess,
   open the floodgates, open the sluices, opening, oppress, out,
   outcome, outfall, outflow, outflowing, outgate, outgo, outlet,
   outpour, outpouring, overact, overcarry, overdevelop, overdo,
   overdrive, overelaborate, overemphasize, overexercise, overexert,
   overexpend, overfatigue, overindulge, overlabor, overplay,
   overreact, overspend, overstrain, overstress, overstudy, overtask,
   overtax, overtire, overtrain, overuse, overweary, overwork, pant,
   pass all bounds, phlebotomize, pick clean, pipette, pluck, poop,
   poop out, pore, port, pour, pour forth, pour out, prey on,
   propellant, propulsion charge, prostrate, protest too much, puff,
   pump, pump out, purge, rattle, reaction propulsion, reduce, reek,
   remove, respire, rocket propulsion, run out, run through, runoff,
   sally port, sap, scour out, send forth, send out, shake, shake up,
   shear, sigh, siphon off, skin, sluice, sluice out, smoke, sneeze,
   sniff, sniffle, snore, snort, snuff, snuffle, soften up, spend,
   spew, spew out, spill, spiracle, spout, spout out, spurt, squander,
   squirt, steam, sterilize, strain, stream, strip, strip bare, suck,
   suck dry, suck out, surge, swallow, swallow up, sweep out, tap,
   tax, throw off, throw out, thrust, tire, tire out, tire to death,
   tucker, unbrace, unclog, undermine, unfoul, unman, unnerve,
   unstrengthen, unstring, use up, vapor, vapor trail, venesect, vent,
   ventage, venthole, void, vomit forth, vomitory, vortex, wake, wash,
   waste, waste away, way out, weaken, wear, wear away, wear down,
   wear on, wear out, wear upon one, weary, weigh upon, weight down,
   weir, well, well out, wheeze, wilt, wind