illiterate vs ignoramus

illiterate and ignoramus both are nouns.

Word	Noun	Adjective	Verb	Adverb
illiterate	Yes	Yes	No	No
ignoramus	Yes	No	No	No

As nouns, ignoramus is a hypernym of illiterate; that is, ignoramus is a word with a broader meaning than illiterate:

Other hypernyms of illiterate include know nothing, uneducated person.

illiterate (noun)	ignoramus (noun)
a person unable to read	an ignorant person

illiterate (adjective)	ignoramus (adjective)
not able to read or write
lacking culture, especially in language and literature
uneducated in the fundamentals of a given art or branch of learning; lacking knowledge of a specific field