WordNet (r) 3.0 (2006):

Haman
    n 1: (Old Testament) the minister of the Persian emperor who
         hated the Jews and was hanged for plotting to massacre them

Easton's 1897 Bible Dictionary:

Haman
   (of Persian origin), magnificent, the name of the vizier (i.e.,
   the prime minister) of the Persian king Ahasuerus (Esther 3:1,
   etc.). He is called an "Agagite," which seems to denote that he
   was descended from the royal family of the Amalekites, the
   bitterest enemies of the Jews, as Agag was one of the titles of
   the Amalekite kings. He or his parents were brought to Persia as
   captives taken in war. He was hanged on the gallows which he had
   erected for Mordecai the Jew (Esther 7:10). (See ESTHER.)


Hitchcock's Bible Names Dictionary (late 1800's):

Haman, noise; tumult