The Collaborative International Dictionary of English v.0.48:

Soot \Soot\ (? or ?; 277), n. [OE. sot, AS. s?t; akin to Icel.
   s?t, Sw. sot, Dan. sod, OD. soet, Lith. s?dis; cf. Gael.
   suith, Ir. suth.]
   A black substance formed by combustion, or disengaged from
   fuel in the process of combustion, which rises in fine
   particles, and adheres to the sides of the chimney or pipe
   conveying the smoke; strictly, the fine powder, consisting
   chiefly of carbon, which colors smoke, and which is the
   result of imperfect combustion. See Smoke.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Soot \Soot\, v. t. [imp. & p. p. Sooted; p. pr. & vb. n.
   Sooting.]
   To cover or dress with soot; to smut with, or as with, soot;
   as, to soot land. --Mortimer.
   [1913 Webster] Soot

The Collaborative International Dictionary of English v.0.48:

Soot \Soot\, Soote \Soot"e\, a. [See Sweet.]
   Sweet. [Obs.] "The soote savour of the vine." --Chaucer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

soot
    n 1: a black colloidal substance consisting wholly or
         principally of amorphous carbon and used to make pigments
         and ink [syn: carbon black, lampblack, soot, smut,
         crock]
    v 1: coat with soot

Moby Thesaurus II by Grady Ward, 1.0:

117 Moby Thesaurus words for "soot":
   air pollution, alluvion, alluvium, ash, ashes, attritus, bedarken,
   begrime, bemire, bemud, besmirch, besmoke, black, blacken,
   blackening, blacking, blackwash, blot, blotch, bran, brand,
   burnt cork, calx, carbon, carbon black, charcoal, cinder, clinker,
   coal, coke, coom, cork, cosmic dust, crow, crumb, crumble, darken,
   denigrate, deposition, deposits, diluvium, dinge, dirt, dirty,
   dirty up, draff, dregs, dross, dust, dust ball, ebon, ebonize,
   ebony, efflorescence, ember, fallout, farina, feces, filings,
   flour, froth, fume, gas black, grime, grits, groats, grounds, ink,
   jet, kittens, lampblack, lava, lees, lint, loess, meal, melanize,
   mire, moraine, muck, muck up, mud, muddy, murk, night, nigrify,
   offscum, oversmoke, pitch, powder, precipitate, precipitation,
   pussies, raspings, raven, reek, sawdust, scoria, scum, sediment,
   settlings, shade, shadow, silt, sinter, slag, slime, sloe, smirch,
   smoke, smudge, smut, smutch, stove black, sublimate, sullage,
   tar