ignorant

Concise Oxford English Dictionary © 2008 Oxford University Press:
ignorant/ˈɪɡnərənt/

▶adjective

• 1 lacking knowledge or awareness in general.

  ■ (often ignorant of) uninformed about or unaware of a specific subject or fact.

• 2 informal discourteous.

• 3 black English easily angered.

– derivatives
ignorance noun,
ignorantly adverb.

– origin ME: via OFr. from L. ignorant-, ignorare (see ignore).