1. In the United Kingdom, a university or college teacher: A don, or professor, instructs at one of the universities of Oxford or Cambridge in England.
2. A Spanish gentleman or aristocrat: Some people remember California in the days of the dons.
3. A head of an organized crime family, especially in the Mafia: A don, or male boss, was found in a cafe in Italy.
4. Etymology: don, as a noun, comes from the 1520's, from Spanish or Portuguese don, a title of respect; which came from Latin dominus, "lord, master".

The university sense appeared about 1660 when it was originally part of student slang. The underworld or criminal sense came about 1952, from Italian don, from Late Latin domnus, which came from Latin dominus. The feminne forms are Dona (Spanish and Portuguese) and Donna (Italian).

1. To put on a piece of clothing on to one's body: Jane donned on a beautiful silk dress that her mother made especially for her.
2. To assume or to take on an attitude or to show one's feelings especially of grief or anger in a demonstrative way: He donned the manner of the injured party when he was not chosen.
3. Etymology: The verbal form of don appeared in about the early 14th century which came from Middle English as a contraction of do on, "put on".