What part of speech is turn off?

"Turn off" can be a few different parts of speech depending on how it's used:

* Phrasal Verb: When used as a verb phrase (like "Turn off the lights"), it functions as a verb.

* Adjective: If it's describing something as being boring or uninteresting, it's acting as an adjective (like "That movie was so turn off").

Let me know if you have a specific sentence in mind, and I can give you a more precise answer.