(1):

(n.) One who boxes; a pugilist.

(2):

(n.) One who packs boxes.

(3):

(n.) A member of a powerful Chinese organization which committed numerous outrages on Europeans and Christian converts in the uprising against foreigners in 1900. Various names, as "League of United Patriots" and "Great Knife [or Sword] Society," have been given as the Chinese name of the organization; why the members were called Boxers is uncertain.