1. 
[syn: clogging, hindering, impeding, obstructive]
The Collaborative International Dictionary of English v.0.48:
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.
   [1913 Webster]
         Whatever hinders or impedes
         The action of the nobler will.           --Logfellow.
   [1913 Webster]
WordNet (r) 3.0 (2006):
impeding
    adj 1: preventing movement; "the clogging crowds of revelers
           overflowing into the street" [syn: clogging,
           hindering, impeding, obstructive]