pig
n.— «Bad jokes flew Friday after a flurry of media reports that a pig caused a train derailment in Saginaw County’s Carrollton Township. Only problem was, the “pig” was a slang reference to a propane tank.» —“Pig stories fly after train derailment” by Cheryl Wade Midland Daily News (Michigan) May 19, 2007. (source: Double-Tongued Dictionary)