Can be confused:ignorant, stupid (see synonym note at the current entry).
Synonyms 1. uninstructed, untutored, untaught. Ignorant,illiterate,unlettered,uneducated mean lacking in knowledge or in training. Ignorant may mean knowing little or nothing, or it may mean uninformed about a particular subject: An ignorant person can be dangerous. I confess I'm ignorant of mathematics. Illiterate originally meant lacking a knowledge of literature or similar learning, but is most often applied now to one unable to read or write: necessary training for illiterate soldiers. Unlettered emphasizes the idea of being without knowledge of literature: unlettered though highly trained in science. Uneducated refers especially to lack of schooling or to lack of access to a body of knowledge equivalent to that learned in schools: uneducated but highly intelligent. 2. unenlightened.
late 14c., from O.Fr. ignorant, from L. ignorantia, from ignorantem, prp. of ignorare from in- "not" + Old L. gnarus "aware, acquainted with," from Porot-L. suffixed form *gno-ro-, related to gnoscere "to know" (see know). Form influenced by ignotus "unknown." Cf. also