Here's how it works:
* Compound noun: A noun formed by combining two or more words.
* Hyphen: A punctuation mark (-) that can be used to join the parts of a compound noun, especially when the words are closely related or the combination is unusual.
Examples:
* Mother-in-law
* High-five
* Check-in
* Passer-by
* Full-time
Let me know if you'd like more examples or have any other questions!