It's possible that:
* It's a misspelling: Perhaps the intended word was "millennial" or something related to the concept of millennials.
* It's a niche term: It could be a term used within a specific community or hobby, like online gaming or a particular type of art.
* It's a joke: The person who used the word might have made it up for comedic effect.
Without more context, it's impossible to determine the exact meaning of "millinophile." If you provide more information about where you encountered the word, I might be able to offer a more helpful answer.