Letter
Letter (alphabet)
One of the signs used to write words, like A or B.
Z is the last letter of the English alphabet.
Letter (message)
A written message sent to someone.
Rohan wrote a letter to his grandmother in Jaipur.
Letter (to the letter)
Exactly as written, in the phrase 'to the letter'.
Arjun followed the recipe to the letter.
Remember: All three grew from one Latin word for a written sign: a sign, a message made of signs, and 'exactly as written'.