The Collaborative International Dictionary of English v.0.48:

Smudge \Smudge\, n. [Cf. Dan. smuds smut, E. smutch, or smoke.]
   1. A suffocating smoke. --Grose.
      [1913 Webster]

   2. A heap of damp combustibles partially ignited and burning
      slowly, placed on the windward side of a house, tent, or
      the like, in order, by the thick smoke, to keep off
      mosquitoes or other insects. [U. S.] --Bartlett.
      [1913 Webster]

   3. That which is smeared upon anything; a stain; a blot; a
      smutch; a smear.
      [1913 Webster]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Smudge \Smudge\, v. t. [imp. & p. p. Smudged; p. pr. & vb. n.
   Smudging.]
   1. To stifle or smother with smoke; to smoke by means of a
      smudge.
      [1913 Webster]

   2. To smear; to smutch; to soil; to blacken with smoke.
      [1913 Webster]

WordNet (r) 3.0 (2006):

smudge
    n 1: a smoky fire to drive away insects
    2: a blemish made by dirt; "he had a smudge on his cheek" [syn:
       smudge, spot, blot, daub, smear, smirch, slur]
    v 1: make a smudge on; soil by smudging [syn: smear, blur,
         smudge, smutch]

Moby Thesaurus II by Grady Ward, 1.0:

137 Moby Thesaurus words for "smudge":
   afterdamp, ash, ashes, aspersion, attaint, badge of infamy,
   bar sinister, baton, bedarken, bedaub, begrime, bend sinister,
   besmear, besmirch, besmutch, besoil, black, black eye, black mark,
   blackdamp, blacken, blackening, blackwash, bloodstain, blot,
   blotch, blur, brand, breath, broad arrow, calx, carbon, censure,
   champain, charcoal, chokedamp, cinder, clinker, cloud, coal, coke,
   coom, cork, dab, damp, darken, darkening, daub, defile, denigrate,
   denigration, dinge, dirty, disparagement, dross, ebonize,
   effluvium, exhalation, eyesore, fetid air, firedamp, flatus, fleck,
   flick, fluid, flyspeck, foul, fume, grime, imputation, ink, lava,
   macula, maculation, macule, malaria, mark, mark of Cain,
   melanization, melanize, mephitis, miasma, murk, nigrification,
   nigrify, onus, oversmoke, patch, pillorying, plaster,
   point champain, puff of smoke, reek, reflection, reprimand,
   reproach, scoria, shade, shading, shadow, slag, slubber, slur,
   smarm, smear, smirch, smirching, smoke, smooch, smouch, smudging,
   smut, smutch, smutching, soil, soilage, soilure, soot, spatter,
   speck, speckle, splash, splatter, splotch, spot, stain, steam,
   stigma, stigmatism, stigmatization, sullage, sully, taint, tarnish,
   vapor, volatile, water vapor