1 definition by Professor LA

The first known use was in the movie Manchester by the Sea. When asked if the nephew was sleeping with a specific girls he answered, "its just basement business", when asked more specifics he simply said I'm working on it.

So basement business is teenage monkey business usually of a sexual nature.
Have you and she had sex even though her mother is home? No it's just {basement business.
by Professor LA July 11, 2017
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