illiteracy

Short definition from Wiktionary

Noun

1. 1
   The inability to read and write.
2. 2
   The portion of a population unable to read and write, generally given as a percentage.
3. 3
   A word, phrase, or grammatical turn thought to be characteristic of an illiterate person.
4. 4
   Unlearnedness; the state of being ignorant or unlettered.