1. Someone who is qualified and licensed to give people medical treatment: Alicia was a doctor or physician who was trained in the healing arts and licensed to practice her skills in one of those fields.
2. A title used before the names of health professionals; such as, dentists, veterinarians, and osteopaths: Dr. is used as a title and form of address for a person holding the degree of doctor.
3. A title given to someone who has been awarded a doctorate: To achieve the degree of doctor is considered to be the highest level of an academic award by a university or college.

In the earlier history of the Roman Catholic Church, a doctor was a very eminent and influential theologian.

1. To change something in order to make it appear different from the facts or the truth: Samuel doctored the costs of the items in an effort to earn more money.

Bill and Dana were accused of doctoring the company's financial records.

2. To add something; especially, a drug, alcohol, or poison, to food or drink: Yvonne suspected that someone at the party doctored the punch.
3. To treat people when they are ill; such as, medical treatment to an injury, a person, etc.: Ted's mother doctored her little girl's injury until the medical people arrived.
4. To fix something; especially, in a rough or hurried way: Kelly was doctoring the hole in the roof of his house until he could get professional carpenters to fix it properly.

Doctor of Literature or Letters.

Doctor of Dental Medicine.

A physician whose medical training is to provide comprehensive medical care for parents and their offspring: The family doctor is a general physician who has been trained to treat illnesses of all of the members of a family; including the very young and the adults.

Doctor of Laws.

Doctor of Laws degree.

Doctor of Literature degree.

Doctor of Medicine.

Doctor of philosophy: Mr. Smith received his Ph.D., or the title of a Philosophiae Doctor, after spending many years at the university, attaining a bachelor's degree with honours, a master's degree with a very high academic standing, and writing a thesis.