The Collaborative International Dictionary of English v.0.48:

Turn-out \Turn"-out`\ (t[^u]rn"out`), n.; pl. Turn-outs
   (t[^u]rn"outs`).
   1. The act of coming forth; a leaving of houses, shops, etc.;
      esp., a quitting of employment for the purpose of forcing
      increase of wages; a strike; -- opposed to lockout.
      [1913 Webster]

   2. A short side track on a railroad, which may be occupied by
      one train while another is passing on a main track; a
      shunt; a siding; a switch.
      [1913 Webster]

   3. That which is prominently brought forward or exhibited;
      hence, an equipage; as, a man with a showy carriage and
      horses is said to have a fine turn-out.
      [1913 Webster]

   4. The aggregate number of persons who have come out, as from
      their houses, for a special purpose; the number in
      attendance at a gathering; as, a light turnout for the
      election.
      [1913 Webster +PJC]

   5. Net quantity of produce yielded.
      [1913 Webster]

   6. A space alongside a highway where vehicles may stop, esp.
      for emergency purposes, or to admire the view.
      [PJC]

WordNet (r) 3.0 (2006):

turnout
    n 1: the group that gathers together for a particular occasion;
         "a large turnout for the meeting"
    2: a part of a road that has been widened to allow cars to pass
       or park [syn: turnout, widening]
    3: a short stretch of railroad track used to store rolling stock
       or enable trains on the same line to pass [syn: siding,
       railroad siding, turnout, sidetrack]
    4: what is produced in a given time period [syn: output,
       outturn, turnout]
    5: a set of clothing (with accessories); "his getup was
       exceedingly elegant" [syn: outfit, getup, rig,
       turnout]
    6: attendance for a particular event or purpose (as to vote in
       an election); "the turnout for the rally"
    7: (ballet) the outward rotation of a dancer's leg from the hip

Moby Thesaurus II by Grady Ward, 1.0:

160 Moby Thesaurus words for "turnout":
   GNP, L, accouterments, apparatus, apparel, assemblage, assemblee,
   assembly, assignation, at home, attendance, audience, ball,
   box office, boycott, boycottage, branch, brawl, cable railway,
   caparison, caucus, clothing, cog railway, colloquium, commission,
   committee, conclave, concourse, congregation, congress,
   conventicle, convention, convocation, council, crowd, dance, date,
   diet, draw, dress, eisteddfod, el, electric railway, elevated,
   elevated railway, embankment, equipage, equipment, feeder,
   feeder line, festivity, fete, fittings, forgathering, forum,
   four-in-hand, frequence, frequenting, furnishings, gate, gathering,
   gear, get-together, getup, gravity-operated railway,
   gross national product, guise, harness, horse railway,
   housewarming, job action, junction, levee, light railroad, line,
   livery, lockout, main line, meet, meeting, metro, monorail, muster,
   number present, outfit, outlaw strike, output, pair, panel, party,
   plenum, product, production, prom, quorum, rack railway,
   rack-and-pinion railway, rail, rail line, railroad, railway, rally,
   randem, reception, rendezvous, revolt, rig, roadbed, roadway,
   rulebook slowdown, seance, session, setout, shindig, sick-in,
   sidetrack, siding, sit-down, sit-down strike, sit-in, sitting,
   slowdown, soiree, span, spike, spike team, street railway,
   streetcar line, strike, subway, switchback, sympathy strike,
   symposium, synod, tandem, team, terminal, terminus, things,
   three-up, throng, tie-up, track, tram, tramline, trappings,
   trestle, trolley line, trousseau, trunk, trunk line, tube,
   underground, unicorn, volume, walkout, wardrobe, wildcat strike,
   work stoppage, yield