WordWeb Online

1. Uneducated in general; lacking knowledge or sophistication
   "an ignorant man"
   - nescient, unlearned, unlettered
    
2. Uneducated in the fundamentals of a given art or branch of learning; lacking knowledge of a specific field
   "she is ignorant of quantum mechanics"
   - illiterate
    
3. Unaware because of a lack of relevant information or knowledge
   "he was completely ignorant of the circumstances"
   - unknowledgeable, unknowing, unwitting

See also: ignorance, ignorantly, ignorantness, uneducated, uninformed

Encyclopedia: Ignorant