Source : Webster's Revised Unabridged Dictionary (1913)

Impede \Im*pede"\, v. t. [imp. & p. p. {Impeded}; p. pr. & vb.
   n. {Impeding}.] [L. impedire, lit., to entangle the feet;
   pref. im- in + pes, pedis, foot. See {Foot}, and cf.
   {Impeach}.]
   To hinder; to stop in progress; to obstruct; as, to impede
   the advance of troops.

         Whatever hinders or impedes The action of the nobler
         will.                                    --Logfellow.

Source : WordNet®

impeded
     adj : made difficult or slow; "we blamed our impeded progress on
           lack of money"