Watching David Cay Johnson explain how he had received the 2005 income tax returns from Mr. and Mrs. Trump, he said that he'd received them "over the transom". A young friend who was visiting asked, "What does that mean?" I explained that it meant unsolicited, sent in secret, or sent without the receiver's knowledge.
It has been years since I have heard the word "transom" or the phrase "over the transom".
My brother asked, "Shouldn't it be THROUGH the transom?"