What part of speech is the word slide?

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

* Noun: A surface that you slide down or across (e.g., "He went down the water slide.")

* Verb: To move smoothly over a surface (e.g., "The children slid across the ice.")

* Adjective: Describing something that slides (e.g., "The slide rule is a tool for calculations.")

To determine the part of speech, you need to look at the context in which it's used.