Wordnet 3.0
NOUN (2)
1.
the literary culture;
- Example: "this book shows American letters at its best"2.
scholarly attainment;
- Example: "he is a man of letters"
WordNet (r) 3.0 (2006):
letters
n 1: the literary culture; "this book shows American letters at
its best"
2: scholarly attainment; "he is a man of letters"