(idiomatic) An honorific form of address to a doctor.

(Southern US) A dragonfly

(medicine, archaic) A physician who treats diseases with water; a hydropathist. / (medicine, archaic) One who claims to be able to divine diseases by inspection of the urine.

A research paper that a student writes in order to complete the requirements for a doctorate; a dissertation.

A clinic where one or more doctors receives patients for their medical care.

A consultant hired to adapt an existing script for use in film, theater, etc.

(obsolete) A physician who treats the insane.

(obsolete) medicine

plural of doctor blade

(informal) A psychiatrist.