Unlettered describes a person who cannot read and write, or more loosely, someone who has had little schooling and has not read many books. It is an old, literary, formal word. A modern writer would say 'illiterate' or 'uneducated'; you meet 'unlettered' in novels, history books, and older writing — 'an unlettered farmer', 'unlettered peasants'. Because of that, it carries a faint air of looking down from above, of an educated writer describing people who are not like them. It can also sound gentler than 'illiterate', almost affectionate, and writers sometimes use it that way on purpose: an unlettered man may still be wise, and English writers rather enjoy that contrast — plain country wisdom against book learning. So the word is not always an insult, though it is never quite neutral either. Note also that it usually means 'has not read the books an educated person is supposed to have read' rather than strictly 'cannot make out the letters' — the two shade into each other. It describes people, and things people do; you would not call a country unlettered except in rather grand writing.

不識字的、沒受過教育的（帶文言、書面味，近似「目不識丁」）