"Proverbial Lemon" refers to anything that doesn't function properly. Commonly used for cars which have problems no one can fix, it can also refer to a flashlight, a radio, or anything mechanical.
Captain Picard: The Federation may be buying a "Proverbial Lemon". (Star Trek: The Next Generation episode "The Price")
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.