Grammar of nouns preceding names

For example:

• Billionaire John Smith purchased a new yacht last week.


• ACME Corporation says it treats workers well, but protestor Jane Doe believes otherwise.

What role do the nouns "billionaire" and "protestor" play here? They seem to be acting as adjectives. They don't seem like noun modifiers to me, as the names are not really being modified.

Answer

The usage is as a noun adjunct. A noun adjunct is a noun that is used to modify another noun. In each of these instances, a noun is being used to modify another noun. The noun adjunct is functioning appositively as a false title.