The Collaborative International Dictionary of English v.0.48:

Risky \Risk"y\, a.
   Attended with risk or danger; hazardous. "A risky matter."
   --W. Collins.
   [1913 Webster]

         Generalization are always risky.         --Lowell.
   [1913 Webster]

WordNet (r) 3.0 (2006):

risky
    adj 1: involving risk or danger; "skydiving is a hazardous
           sport"; "extremely risky going out in the tide and fog";
           "a wild financial scheme" [syn: hazardous, risky,
           wild]
    2: not financially safe or secure; "a bad investment"; "high
       risk investments"; "anything that promises to pay too much
       can't help being risky"; "speculative business enterprises"
       [syn: bad, risky, high-risk, speculative]

Moby Thesaurus II by Grady Ward, 1.0:

79 Moby Thesaurus words for "risky":
   accidental, adventitious, adventurous, aleatory, blue, broad,
   casual, causeless, chance, chancy, contingent, dangerous, delicate,
   destinal, desultory, dicey, fatal, fatidic, fluky, fortuitous,
   full of risk, hairy, hazardous, iffy, incidental, indeterminate,
   infirm, insecure, insubstantial, jeopardous, off-color,
   on thin ice, perilous, precarious, provisional, racy, riskful,
   risque, salty, scabrous, sensitive, shady, shaky, shifting, shifty,
   slippery, speculative, spicy, suggestive, temporary, tentative,
   ticklish, touch-and-go, touchy, treacherous, uncaused, uncertain,
   undependable, undetermined, unexpected, unfaithworthy,
   unforeseeable, unforeseen, unhealthy, unlooked-for, unpredictable,
   unreliable, unsolid, unsound, unstable, unsteadfast, unsteady,
   unsubstantial, unsure, untrustworthy, venturesome, venturous,
   wicked, wildcat