What does mean to be lavaliered by fraternity boy?

There's no established meaning for "lavaliered by a fraternity boy." The word "lavalier" typically refers to a type of microphone or a small piece of jewelry. Neither of these fits the context of a fraternity boy interaction.

It's possible this is:

* A neologism or slang: A newly coined word or phrase used within a specific group or context. Without more information about where you encountered this term, it's impossible to say what it means.

* A misspelling or mishearing: Perhaps a different word was intended, such as "assaulted," "hazed," "propositioned," or another term related to potentially negative interactions within a fraternity.

* A made-up term: It could simply be a term invented for a fictional story or situation.

If you can provide more context, such as the source where you saw this phrase, I might be able to offer a more accurate interpretation.