The Collaborative International Dictionary of English v.0.48:

Publican \Pub"li*can\, n. [L. publicanus: cf. F. publicain. See
   Public.]
   1. (Rom. Antiq.) A farmer of the taxes and public revenues;
      hence, a collector of toll or tribute. The inferior
      officers of this class were often oppressive in their
      exactions, and were regarded with great detestation.
      [1913 Webster]

            As Jesus at meat . . . many publicans and sinners
            came and sat down with him and his disciples.
                                                  --Matt. 1x.
                                                  10.
      [1913 Webster]

            How like a fawning publican he looks! --Shak.
      [1913 Webster]

   2. The keeper of an inn or public house; one licensed to
      retail beer, spirits, or wine.
      [1913 Webster]

WordNet (r) 3.0 (2006):

publican
    n 1: the keeper of a public house [syn: publican, tavern
         keeper]

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "publican":
   Internal Revenue Service, assessor, barkeep, barkeeper, barmaid,
   barman, bartender, bootlegger, brewer, brewmaster, customhouse,
   customs, distiller, exciseman, farmer, liquor dealer,
   liquor store owner, mixologist, moonshiner, revenuer, tapster,
   tapstress, tax assessor, tax collector, tax farmer, taxer, taxman,
   vintner, wine merchant



Easton's 1897 Bible Dictionary:

Publican
   one who farmed the taxes (e.g., Zacchaeus, Luke 19:2) to be
   levied from a town or district, and thus undertook to pay to the
   supreme government a certain amount. In order to collect the
   taxes, the publicans employed subordinates (5:27; 15:1; 18:10),
   who, for their own ends, were often guilty of extortion and
   peculation. In New Testament times these taxes were paid to the
   Romans, and hence were regarded by the Jews as a very heavy
   burden, and hence also the collectors of taxes, who were
   frequently Jews, were hated, and were usually spoken of in very
   opprobrious terms. Jesus was accused of being a "friend of
   publicans and sinners" (Luke 7:34).


Bouvier's Law Dictionary, Revised 6th Ed (1856):

PUBLICAN, civil law. A farmer of the public revenue; one who held a lease of
some property from the public treasury. Dig. 39, 4, 1, 1; Id. 39, 4, 12, 3;
Id. 39, 4, 13.