Baretti: A dictionary of the English and Italian languages
Létter-a, s. f. dim. Létter-étta, Létter-ína, Létter-íno, Létter-úccia, Létter-úzza, aug. Létter-óne, disp. Létter-áccia,
1. letter, character of the alphabet. — vocale, a vowel. — consonante,a consonant. — d'oro, letter written in gold. — majuscola, a capital letter. Dire, parlare a — di scatola, di speziali, &c., to speak clearly, plainly. — iniziale, an initial letter;2. word; 3. writing; 4. letters, literature.Essere di —, lettered, learned. Saper —, to know one's letters, to know how to write. Uomo senza —, an ignorant man; 5. written word. Secondo la — or le scritture, according to the letters, the strict meaning; 6. reading;7. sentence; 8. letter, epistle. — di favore,letter of introduction. — di credenza, credentials, letter of credence (of an ambassador, &c.), of credit (upon a banker). — di procura, letter of attorney. — cieca, a letter without address, or with an erroneous one. — di cambio, bill of exchange. — d'avviso, letter of advice. — pontificia, a brief. Belle lettere, the belles lettres, polite literature, the humanities.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
lettera: a letter, a caracter. Also an epistle, a letter, a missiue or any writing. Also literature or learning.