Definition of "Doctor" :
noun: children take the roles of physician or patient or nurse and pretend they are at the physician's office
"The children explored each other's bodies by playing the game of doctor."
noun: a licensed medical practitioner
"I felt so bad I went to see my doctor."
noun: a person who holds Ph.D. degree (or the equivalent) from an academic institution
"She is a doctor of philosophy in physics."
noun: (Roman Catholic Church) a title conferred on 33 saints who distinguished themselves through the orthodoxy of their theological teaching
"The Doctors of the Church greatly influenced Christian thought down to the late Middle Ages."
verb: give medical treatment to
verb: restore by replacing a part or putting together what is torn or broken
verb: alter and make impure, as with the intention to deceive