What part of speech is the word doctor?

The word "doctor" can be several parts of speech depending on how it's used in a sentence:

* Noun: When referring to a person with a medical degree.

* Example: "The doctor examined the patient."

* Verb: When it means to treat or alter something.

* Example: "The chef doctored the sauce with a little more salt."

* Adjective: This is less common, but can be used to describe something that is related to a doctor or medicine.

* Example: "He received doctor's orders to rest."

So, to determine the part of speech, you need to consider the context of the sentence.