What part of speech is the word healthy?

The word "healthy" can be a few different parts of speech, depending on its function in a sentence:

* Adjective: Describing a noun. Example: "She eats a healthy diet."

* Adverb: Modifying a verb, adjective, or another adverb. Example: "The doctor advised him to eat healthily."

* Noun: Referring to the state of being healthy. Example: "She is concerned about her health."

So, without context, it's impossible to say definitively which part of speech "healthy" is.