The comparatively nonvolatile residue from the burning of cigarette tobacco that appears in finely divided form in the smoke. Cigarette tar is known to contain various aromatic ring compounds (especially benzo[a]pyrene), also found in coal tar, that are carcinogens. Various forms of activated carbon are used in filters to try to adsorb the toxic components of the tars that find their way into the smoke.See Smoke (5).