Definition of "illiteracy"

(uncountable) The inability to read and write.  examples

(uncountable) The portion of a population unable to read and write, generally given as a percentage.  examples

(countable) A word, phrase, or grammatical turn thought to be characteristic of an illiterate person.  examples

(uncountable, by extension) Unlearnedness; the state of being ignorant or unlettered.  examples