noun

1. Archaic a teacher or learned man
2. a person who holds a doctorate
3. a physician or surgeon (MD)
4. a person licensed to practice any of the healing arts, as an osteopath, dentist, veterinarian, etc.
5. a title used in addressing any person who holds a doctorate
6. a witch doctor or medicine man
7. a makeshift device, apparatus, etc., for emergency use
8. a bright-colored artificial fly used in fishing

Etymology: ME doctour, teacher, learned man < OFr or < L doctor, teacher < pp. of docere, to teach: see decent

transitive verb

1. to try to heal; apply medicine to
2. to repair; mend
3. to make suitable or improve by altering in a certain way
4. to tamper with or change in order to deceive to doctor accounts

intransitive verb

1. Informal to practice medicine
2. ☆ Dialectal to undergo medical treatment, take medicine, etc.