doc·tor 
(dŏktər)
(dŏktər)n.
1.
a. A person who is licensed to practice medicine and has trained at a school of medicine or a school of osteopathic medicine; a physician.
b. Any of certain other healthcare professionals, such as a dentist, optometrist, chiropractor, podiatrist, or veterinarian.
2. A practitioner of alternative medicine or folk medicine who does not have traditional medical credentials.
3.
a. A person who has earned the highest academic degree, usually a PhD, awarded by a college or university in a specified discipline.
b. A person awarded an honorary degree by a college or university.
4. Abbr. Dr. Used as a title and form of address for a person holding the degree of doctor.
5. Roman Catholic Church An eminent theologian.
6. A rig or device contrived for remedying an emergency situation or for doing a special task.
v. doc·tored, doc·tor·ing, doc·tors
v.tr.
1. Informal To give medical treatment to: "[He] does more than practice medicine. He doctors people. There's a difference" (Charles Kuralt).
2. To repair, especially in a makeshift manner; rig.
3.
a. To falsify or change in such a way as to make favorable to oneself: doctored the evidence.
b. To add ingredients so as to improve or conceal the taste, appearance, or quality of: doctor the soup with a dash of sherry.
c. To alter or modify for a specific end: doctored my standard speech for the small-town audience.
d. Baseball To deface or apply a substance to (the ball) in violation of the rules in order to throw a pitch with extraordinary movement: was ejected because he doctored the ball with a piece of sandpaper.
v.intr.
Informal
Informal
To practice medicine.
[Middle English, an expert, authority, from Old French docteur, from Latin doctor, teacher, from docēre, to teach; see dek- in the Appendix of Indo-European roots.]
doctor·al (dŏktə-rəl, dŏk-tôrəl) adj.
doctor·ly adj.