Source : Webster's Revised Unabridged Dictionary (1913)

Chanceful \Chance"ful\, a.
   Hazardous. [Obs.] --Spenser.

Source : WordNet®

chanceful
     adj : of uncertain outcome; especially fraught with risk; "an
           extremely dicey future on a brave new world of liquid
           nitrogen, tar, and smog"- New Yorker [syn: {chancy}, {dicey},
            {dodgy}]