The Collaborative International Dictionary of English v.0.48:

Impediment \Im*ped"i*ment\, v. t.
   To impede. [R.] --Bp. Reynolds.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Impediment \Im*ped"i*ment\, n. [L. impedimentum: cf. F.
   impediment.]
   That which impedes or hinders progress, motion, activity, or
   effect.
   [1913 Webster]

         Thus far into the bowels of the land
         Have we marched on without impediment.   --Shak.
   [1913 Webster]

   Impediment in speech, a defect which prevents distinct
      utterance.

   Syn: Hindrance; obstruction; obstacle; difficulty;
        incumbrance.

   Usage: Impediment, Obstacle, Difficulty, Hindrance.
          An impediment literally strikes against our feet,
          checking our progress, and we remove it. An obstacle
          rises before us in our path, and we surmount or remove
          it. A difficulty sets before us something hard to be
          done, and we encounter it and overcome it. A hindrance
          holds us back for a time, but we break away from it.
          [1913 Webster]

                The eloquence of Demosthenes was to Philip of
                Macedon, a difficulty to be met with his best
                resources, an obstacle to his own ambition, and
                an impediment in his political career. --C. J.
                                                  Smith.
          [1913 Webster]

WordNet (r) 3.0 (2006):

impediment
    n 1: something immaterial that interferes with or delays action
         or progress [syn: hindrance, hinderance, deterrent,
         impediment, balk, baulk, check, handicap]
    2: any structure that makes progress difficult [syn:
       obstruction, obstructor, obstructer, impediment,
       impedimenta]

Moby Thesaurus II by Grady Ward, 1.0:

107 Moby Thesaurus words for "impediment":
   arrest, arrestation, arrestment, bar, barrier, blank wall,
   blind alley, blind gut, block, blockade, blockage, blocking,
   bottleneck, burden, burthen, cargo, cecum, charge, check, choking,
   choking off, clog, clogging, closing up, closure, congestion,
   constipation, constriction, costiveness, cramp, cross, cul-de-sac,
   cumbrance, curb, dead end, deadweight, delay, detainment,
   detention, difficulty, disadvantage, embarrassment, embolism,
   embolus, encumbrance, fixation, foot-dragging, freight, gorge,
   hamper, hampering, handicap, hang-up, hindering, hindrance, hitch,
   hold-up, holdback, holdup, hurdle, impasse, impedance, impedimenta,
   imposition, inconvenience, infarct, infarction, inhibition,
   interference, interruption, jam, let, load, lumber, mountain,
   negativism, nuisance value, obstacle, obstipation, obstruction,
   obstructionism, occlusion, onus, opposition, pack, penalty,
   repression, resistance, restraint, restriction, retardation,
   retardment, rub, sealing off, setback, snag, squeeze, stop,
   stoppage, stranglehold, strangulation, stricture, stumbling block,
   suppression, trouble, weight, white elephant