well-read vs lettered

well-read and lettered both are adjectives.

Word	Noun	Adjective	Verb	Adverb
well-read	No	Yes	No	No
lettered	No	Yes	No	No

As adjectives, well-read and lettered are synonyms defined as:

well-read and lettered: highly educated; having extensive information or understanding

Other synonyms of well-read include knowing, knowledgeable, learned, well-educated.

well-read (adjective)	lettered (adjective)
highly educated; having extensive information or understanding	highly educated; having extensive information or understanding
well informed or deeply versed through reading