The Collaborative International Dictionary of English v.0.48:

Repetition \Rep`e*ti"tion\ (r[e^]p`[-e]-t[i^]sh"[u^]n), n. [L.
   repetitio: cf. F. r['e]p['e]tition. See Repeat.]
   1. The act of repeating; a doing or saying again; iteration.
      [1913 Webster]

            I need not be barren of accusations; he hath faults,
            with surplus to tire in repetition.   --Shak.
      [1913 Webster]

   2. Recital from memory; rehearsal.
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   3. (Mus.) The act of repeating, singing, or playing, the same
      piece or part a second time; reiteration of a note.
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   4. (Rhet.) Reiteration, or repeating the same word, or the
      same sense in different words, for the purpose of making a
      deeper impression on the audience.
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   5. (Astron. & Surv.) The measurement of an angle by
      successive observations with a repeating instrument.
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   Syn: Iteration; rehearsal. See Tautology.
        [1913 Webster] Repetitional

Moby Thesaurus II by Grady Ward, 1.0:

139 Moby Thesaurus words for "repetition":
   ceaselessness, chattering, clockwork regularity, clone,
   conduplication, constancy, constant flow, continualness,
   continuance, continuation, continuity, copy, copying,
   counterfeiting, counterpart, ditto, double, doubling, dupe,
   duplicate, duplication, echo, echoing, emulation, endurance,
   evenness, extension, facsimile, fakery, following, forgery,
   gemination, hit-off, imitation, impersonation, imposture,
   impression, incessancy, ingemination, iteration, lengthening,
   maintenance, methodicalness, mimesis, mirroring, model,
   noninterruption, onomatopoeia, oscillation, palingenesis, parody,
   perpetuation, perpetuity, perseverance, persistence, plagiarism,
   plagiary, progress, progression, prolongation, protraction,
   pulsation, punctuality, pursuance, quadruplicate, quick fire,
   rapid fire, rapid recurrence, rapid succession, rapidity,
   re-creation, re-formation, rebirth, rebuilding, recapitulation,
   recital, reconstitution, reconstruction, redesign, redoing,
   redundancies, redundancy, reduplication, reedition,
   reestablishment, refashioning, regeneration, regenesis, regularity,
   rehearsal, reinstitution, reissue, reiteration, remaking,
   renascence, renovation, reorganization, repeat, repeating, replica,
   replication, representation, reprinting, reprise, reproduction,
   rerun, reshaping, restatement, restoration, restructuring,
   resurrection, retelling, revision, revival, run, simulation,
   smoothness, staccato, staying power, steadiness, straight course,
   stuttering, sustained action, sustainment, sustenance,
   systematicalness, takeoff, tattoo, tautologies, tautology,
   triplicate, twinning, uniformity, unintermission,
   uninterrupted course, uninterruption, unremittingness, vibration,
   way