The Collaborative International Dictionary of English v.0.48:

Elimination \E*lim`i*na"tion\, n. [Cf. F. ['e]limination.]
   1. The act of expelling or throwing off; (Physiol.) the act
      of discharging or excreting waste products or foreign
      substances through the various emunctories.
      [1913 Webster]

   2. (Alg.) Act of causing a quantity to disappear from an
      equation; especially, in the operation of deducing from
      several equations containing several unknown quantities a
      less number of equations containing a less number of
      unknown quantities.
      [1913 Webster]

   3. The act of obtaining by separation, or as the result of
      eliminating; deduction. [See Eliminate, 4.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

elimination
    n 1: the act of removing or getting rid of something [syn:
         elimination, riddance]
    2: the bodily process of discharging waste matter [syn:
       elimination, evacuation, excretion, excreting,
       voiding]
    3: analysis of a problem into alternative possibilities followed
       by the systematic rejection of unacceptable alternatives
       [syn: elimination, reasoning by elimination]
    4: the act of removing an unknown mathematical quantity by
       combining equations
    5: the murder of a competitor [syn: elimination,
       liquidation]

Moby Thesaurus II by Grady Ward, 1.0:

104 Moby Thesaurus words for "elimination":
   abolishment, abolition, abscission, amputation, annihilation,
   annulment, assassination, bloody murder, bumping-off, castaway,
   castoff, choking, choking off, cleaning out, clearance, clearing,
   deep six, defecation, depletion, deportation, deracination,
   destruction, detachment, discard, discarding, discharge,
   discharging cargo, disjunction, disposal, disposition, drainage,
   draining, dumping, effusion, egestion, egress, ejaculation,
   ejection, emission, emptying, eradication, evacuation, excision,
   exclusion, excretion, exhausting, exhaustion, exile, expatriation,
   expulsion, extermination, extinction, extinguishment, extirpation,
   extravasation, extrusion, exudation, flow, flux, foul play,
   homicide, jettison, junking, liquidation, manslaughter, murder,
   mutilation, negation, nullification, off-loading, ostracism,
   outlawing, outlawry, purge, purging, refuse, reject, rejectamenta,
   rejection, removal, rescission, riddance, rooting out, scrapping,
   secretion, severance, silencing, snuffing out, stifling,
   strangulation, suffocation, suppression, suspension, throwaway,
   thuggee, thuggery, thuggism, transudation, unloading, uprooting,
   venting, voidance, voiding, withdrawal