Source : Webster's Revised Unabridged Dictionary (1913)

Dominican \Do*min"i*can\, a. [NL. Dominicanus, fr. Dominicus,
   Dominic, the founder: cf. F. Dominicain.]
   Of or pertaining to St. Dominic (Dominic de Guzman), or to
   the religions communities named from him.

   {Dominican nuns}, an order of nuns founded by St. Dominic,
      and chiefly employed in teaching.

   {Dominican tertiaries} (the third order of St. Dominic). See
      {Tertiary}.

Dominican \Do*min"i*can\, n. (Eccl. Hist.)
   One of an order of mendicant monks founded by Dominic de
   Guzman, in 1215. A province of the order was established in
   England in 1221. The first foundation in the United States
   was made in 1807. The Master of the Sacred Palace at Rome is
   always a Dominican friar. The Dominicans are called also
   {preaching friars}, {friars preachers}, {black friars} (from
   their black cloak), {brothers of St. Mary}, and in France,
   {Jacobins}.

Source : WordNet®

Dominican
     adj 1: of or relating to or characteristic of the Dominican
            Republic or its people; "the Dominican population"
     2: of or relating to Saint Dominic or the Dominican order;
        "Dominican monks"

Dominican
     n : a Roman Catholic friar wearing the black mantle of the
         Dominican order [syn: {Black Friar}, {Blackfriar}, {friar
         preacher}]