The Collaborative International Dictionary of English v.0.48:

Changeful \Change"ful\, a.
   Full of change; mutable; inconstant; fickle; uncertain.
   --Pope.
   [1913 Webster]

         His course had been changeful.           --Motley.
   -- Change"ful*ly, adv. -- Change"ful*ness, n.
   [1913 Webster]