What type of a word is doubt?

"Doubt" can be classified as several types of words, depending on the context:

* Noun: It refers to a feeling of uncertainty or lack of conviction. Example: "He had doubt in his mind about the plan."

* Verb: It means to be uncertain or to question the truth of something. Example: "I doubt that he will come."

* Adjective: (less common) It can describe something that is uncertain or questionable. Example: "His victory was a doubtful one."

So, the type of word "doubt" is depends on how it's used in a sentence.