noun

1. a written or printed symbol employed to represent a speech sound or sounds; character in an alphabet: in some languages, as English, some words contain letters that are no longer sounded
2. a written or printed message to a person or group, usually sent by mail in an envelope
3. an official document giving certain authorities or privileges: usually used in pl.
4. 1. literature generally
   2. learning; knowledge, esp. of literature
5. strict interpretation of the literal meaning, or the literal meaning itself; exact wording
6. ☆ a cloth representation of the first letter of the name of a school or college, awarded and worn for superior performance in sports, etc.
7. Printing
   1. a type, impression, or photographic reproduction of a character of the alphabet
   2. a particular style of type

Etymology: ME lettre < OFr < L littera, letter of the alphabet, (in pl.) a letter, epistle

transitive verb

1. to make hand-printed letters on; mark with letters to letter a poster
2. to set down in hand-printed letters to letter one's name

intransitive verb

1. to make hand-printed letters
2. ☆ Informal to earn a school letter as in a sport