The Collaborative International Dictionary of English v.0.48:

Unchancy \Un*chan"cy\, a. [Pref un- + Scot. chancy fortunate,
   safe.]
   1. Happening at a bad time; unseasonable; inconvenient. --A.
      Trollope.
      [1913 Webster]

   2. Ill-fated; unlucky. [Prov. Eng. & Scot.]
      [1913 Webster]

   3. Unsafe to meddle with; dangerous. [Scot.]
      [1913 Webster]