What part of speech is irrational?

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

* Adjective: Describing something that lacks reason or logic.

* Example: "He made an irrational decision."

* Noun: A number that cannot be expressed as a simple fraction.

* Example: "Pi is an irrational number."

It's important to consider the context of the sentence to determine the correct part of speech.