Merriam-Webster Collegiate Dictionary - don

 I. transitive verb  (~ned; ~ning)  Etymology: Middle English, contraction of do on  Date: 14th century  1. to put on (an article of clothing)  2. to wrap oneself in ; take on 3a  II. noun  Etymology: Spanish, from Latin dominus master — more at dame  Date: 1523  1. a Spanish nobleman or gentleman — used as a title prefixed to the Christian name  2. archaic a person of consequence ; grandee  3. a head, tutor, or fellow in a college of Oxford or Cambridge University; broadly a college or university professor  4. Italian, title of respect, from ~no, literally, lord, from Latin dominus a powerful Mafia leader DON  abbreviation director of nursing DON  geographical name river 1224 miles (1969 kilometers) Russia in Europe flowing SE & then SW into Sea of Azov