"a letter," is used in the plural in Acts 26:24 , with the meaning "learning:" "(thy much) learning (doth turn thee to madness)," RV, possibly an allusion to the Jewish Scriptures, to which the Apostle had been appealing; in John 7:15 , "(How knoweth this Man) letters" (AV marg., "learning"), the succeeding phrase "not having learned" is illustrated in the papyri, where it indicates inability to write. See BILL.
"teaching, instruction" (akin to didasko, "to teach"), is translated "learning" in Romans 15:4 . See DOCTRINE.