The Collaborative International Dictionary of English v.0.48:

Mistrustful \Mis*trust"ful\, a.
   Having or causing mistrust, suspicions, or forebodings.
   [1913 Webster]

         Their light blown out in some mistrustful wood. --Shak.
   [1913 Webster] -- Mis*trust"ful*ly, adv. --
   Mis*trust"ful*ness, n.
   [1913 Webster]