Here's a breakdown:
* Interjection: A word or phrase that expresses strong emotion and is often used independently from a sentence. Examples: Wow! Ouch! Yikes!
* Noun: A word that names a person, place, thing, or idea. Examples: cat, house, happiness, freedom.
Therefore, an interjection noun is a noun that is used to express strong emotion, like an interjection.
Here are some examples:
* "Goodness! That was a close call." (Goodness is a noun used as an interjection to express surprise.)
* "Rats! I forgot my keys." (Rats is a noun used as an interjection to express frustration.)
* "Heaven! That was delicious!" (Heaven is a noun used as an interjection to express pleasure.)
It's important to note that interjection nouns are not always formally recognized as nouns in dictionaries. However, their use in this way is common and understood in language.