What part of speech is the word fluid?

The word "fluid" can be several parts of speech depending on its use in a sentence:

* Adjective: Describing something that flows easily, like "a fluid motion" or "a fluid design."

* Noun: Referring to a substance that flows easily, like "a fluid like water" or "the body's fluids."

Therefore, it's essential to consider the context of the sentence to determine the correct part of speech for "fluid."