The Collaborative International Dictionary of English v.0.48:

Turbid \Tur"bid\ (t[^u]r"b[i^]d), a. [L. turbidus, from turba
   tumult, disturbance, akin to turbare to disturb. See
   Trouble, and cf. Disturb, Perturb.]
   1. Not clear; having suspended matter that scatters light
      passing through; having the lees or sediment disturbed;
      roiled; muddy; thick; -- used of liquids of any kind; as,
      turbid water; turbid wine.
      [1913 Webster]

            On that strong, turbid water, a small boat,
            Guided by one weak hand, was seen to float.
                                                  --Whittier.
      [1913 Webster]

   2. Disturbed; confused; disordered. " Such turbid intervals
      that use to attend close prisoners." --Howell.
      [1913 Webster]

WordNet (r) 3.0 (2006):

turbid
    adj 1: (of liquids) clouded as with sediment; "a cloudy liquid";
           "muddy coffee"; "murky waters" [syn: cloudy, muddy,
           mirky, murky, turbid]

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "turbid":
   adiaphanous, amiss, askew, awry, cloudy, cockeyed, convulsed, dark,
   deranged, dirty, disarranged, discomfited, discomposed,
   disconcerted, dislocated, disordered, disorderly, disorganized,
   disturbed, grumly, haywire, impervious to light, in disorder,
   intransparent, miry, misplaced, mucky, muddy, obscure,
   on the fritz, oozy, opaque, out of gear, out of joint,
   out of kelter, out of kilter, out of order, out of place,
   out of tune, out of whack, perturbed, plashy, roiled, roily,
   shuffled, slabby, slobby, sloppy, sloshy, sloughy, sludgy, slushy,
   soft, splashy, sposhy, squashy, squelchy, squishy, turbulent,
   unsettled, upset