The Collaborative International Dictionary of English v.0.48:

Exposure \Ex*po"sure\ (?;135), n. [From Expose.]
   1. The act of exposing or laying open, setting forth, laying
      bare of protection, depriving of care or concealment, or
      setting out to reprobation or contempt.
      [1913 Webster]

            The exposure of Fuller . . . put an end to the
            practices of that vile tribe.         --Macaulay.
      [1913 Webster]

   2. The state of being exposed or laid open or bare; openness
      to danger; accessibility to anything that may affect,
      especially detrimentally; as, exposure to observation, to
      cold, to inconvenience.
      [1913 Webster]

            When we have our naked frailties hid,
            That suffer in exposure.              --Shak.
      [1913 Webster]

   3. Position as to points of compass, or to influences of
      climate, etc. "Under a southern exposure." --Evelyn.
      [1913 Webster]

            The best exposure of the two for woodcocks. --Sir.
                                                  W. Scott.
      [1913 Webster]

   4. (Photog.) The exposing of a sensitized plate to the action
      of light.
      [1913 Webster]

WordNet (r) 3.0 (2006):

exposure
    n 1: vulnerability to the elements; to the action of heat or
         cold or wind or rain; "exposure to the weather" or "they
         died from exposure";
    2: the act of subjecting someone to an influencing experience;
       "she denounced the exposure of children to pornography"
    3: the disclosure of something secret; "they feared exposure of
       their campaign plans"
    4: aspect resulting from the direction a building or window
       faces; "the studio had a northern exposure"
    5: the state of being vulnerable or exposed; "his vulnerability
       to litigation"; "his exposure to ridicule" [syn:
       vulnerability, exposure]
    6: the intensity of light falling on a photographic film or
       plate; "he used the wrong exposure"
    7: a representation of a person or scene in the form of a print
       or transparent slide; recorded by a camera on light-sensitive
       material [syn: photograph, photo, exposure, picture,
       pic]
    8: the act of exposing film to light
    9: presentation to view in an open or public manner; "the
       exposure of his anger was shocking"
    10: abandoning without shelter or protection (as by leaving as
        infant out in the open)

Moby Thesaurus II by Grady Ward, 1.0:

215 Moby Thesaurus words for "exposure":
   ASA exposure index, DIN number, PR, acquaintance, airing,
   apocalypse, apparition, appearance, appearing, arising, aspect,
   attitude, avatar, azimuth, ballyhoo, baring, bearing, bearings,
   blurb, bright light, bringing to light, casual discovery, catching,
   celebrity, celestial navigation, chance discovery, coming,
   coming into being, coming-forth, common knowledge, communicating,
   communication, contact, cry, currency, danger, daylight,
   dead reckoning, defenselessness, demonstration, denudation,
   desquamation, detection, determination, determining, direction,
   discernibleness, disclosing, disclosure, disconfirmation,
   discovering, discovery, display, disproof, disproval, disproving,
   distinguishment, divestment, divulging, eclat, emergence,
   enactment, endangerment, epiphany, espial, excavation, excoriation,
   exfoliation, exhibit, exhibition, exhibitionism, exhumation,
   experience, explosion, expose, exposition, exposure meter, f-stop,
   fame, familiarity, famousness, film rating, film speed, find,
   finding, finding out, fix, forthcoming, frontage, glare, hazard,
   helplessness, hoopla, hue and cry, imperilment, incarnation,
   indecent exposure, invalidation, invention, issuance, jeopardy,
   knowledge, lay, laying bare, laying open, leak, leaking,
   lens opening, liability, lie, light meter, limelight,
   line of position, locating, location, lucky strike, manifestation,
   materialization, materializing, maximum dissemination, nakedness,
   negation, nonimmunity, notoriety, observability, occurrence,
   opening, openness, orientation, ostentation, outcrop, outcropping,
   outlook, patefaction, perceptibility, performance, peril, pilotage,
   plug, position, position line, presentation, presentment,
   press notice, production, projection, public eye, public knowledge,
   public relations, public report, publication, publicity,
   publicity story, publicness, publishing, puff, radio bearing,
   realization, reclame, recognition, redargution, rediscovery,
   reductio ad absurdum, removal, removing the veil, report,
   representation, retrospective, revealing, revealment, revelation,
   rise, rising, risk, seeableness, serendipity, set, setting, show,
   showing, showing forth, showing up, showup, shutter speed,
   spotlight, spotting, strike, stripping, susceptibility,
   susceptivity, the seen, the visible, theophany, time exposure,
   treasure trove, trouvaille, trove, uncloaking, uncovering,
   unearthing, unfolding, unfoldment, unmasking, unprotection,
   unveiling, unwrapping, varnishing day, vernissage, view,
   visibility, visibleness, visuality, vulnerability,
   what is revealed, write-up