NOUN (3)

1. a member of the tall Negroid people of eastern South Africa; some live in KwaZulu-Natal under the traditional clan system but many now work in the cities;

2. a community of Negroid people in eastern South Africa;

3. a Bantu language of considerable literary importance in southeastern Africa;

The Collaborative International Dictionary of English v.0.48:

Zulus \Zu"lus\ (z[=oo]"l[=oo]z), prop. n. pl.; sing. Zulu
   (z[=oo]"l[=oo]). (Ethnol.)
   The most important tribe belonging to the Kaffir race. They
   inhabit a region on the southeast coast of Africa, but
   formerly occupied a much more extensive country. They are
   noted for their warlike disposition, courage, and military
   skill.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Zulu \Zu"lu\ (z[=oo]"l[=oo]), prop. n. [Also Zooloo.]
   1. Any member of the tribe of Zulus; a Zulu-Kaffir. See
      Zulus.
      [Webster 1913 Suppl.]

   2. (Philol.) One of the most important members of the South
      African, or Bantu, family of languages, spoken partly in
      Natal and partly in Zululand, but understood, and more or
      less in use, over a wide territory, at least as far north
      as the Zambezi; -- called also Zulu-Kaffir.
      [Webster 1913 Suppl.]

   3. A word used in spoken communications to represent the
      letter Z.
      [PJC]

WordNet (r) 3.0 (2006):

Zulu
    n 1: a member of the tall Negroid people of eastern South
         Africa; some live in KwaZulu-Natal under the traditional
         clan system but many now work in the cities
    2: a community of Negroid people in eastern South Africa
    3: a Bantu language of considerable literary importance in
       southeastern Africa