Definition of "Letter" :

noun: a written message addressed to a person or organization

"Mailed an indignant letter to the editor."

noun: an award earned by participation in a school sport

"He won letters in three sports."

noun: the conventional characters of the alphabet used to represent speech

"His grandmother taught him his letters."

noun: a strictly literal interpretation (as distinct from the intention)

"He followed instructions to the letter."

noun: owner who lets another person use something (housing usually) for hire

verb: mark letters on or mark with letters

verb: set down or print with letters

verb: win an athletic letter