Definitions
1.AdjectiveUnable to read and write."About half of the population in Ethiopia is illiterate."
2.AdjectiveHaving less than an expected standard of familiarity with language and literature, or having little formal education.
3.AdjectiveNot conforming to prescribed standards of speech or writing.
4.AdjectiveIgnorant in a specified way or about a specified subject."technologically illiterate, economically illiterate, emotionally illiterate"
5.NounAn illiterate person, one either not able to read and write or not knowing how.
6.NounA person ignorant about a given subject. (The relevant subject is usually named as a noun adjunct.)"Their government is run by business illiterates.; Sometimes a mathematical illiterate is called an innumerate."