* Meaning: "Adult" typically stands alone as a complete word, describing a person who has reached legal age.
* Usage: Compound words often combine nouns or adjectives to create a new concept. "Adult" is usually used as a descriptor rather than a component in a combined word.
Possible, but not common:
* Adult-only: This is a phrase often used to describe something restricted to adults.
* Adult-sized: This describes something appropriate for adults in size.
It's important to note that while these are technically compound words, they are not frequently used.