sag wagon
n.— «The cyclists said they carry about 10 pounds of weight with them when they ride. The rest of their equipment and belongings travel with Barrett in the support vehicle or “sag” wagon, as they call it.» —“Cyclists visit Waterville en route to Key West” by Doug Harlow Morning Sentinel (Waterville, Maine) Sept. 16, 2004. (source: Double-Tongued Dictionary)
Further reading
How do you pronounce the word route? Does it rhyme with “boot” or “bout”? This is part of a complete episode.
Related
Cat hair may be something you brush off, but cat hair is also a slang term that means “money.” In the same way, cat beer isn’t alcoholic — some people use cat beer as a joking term for “milk.” And imagine walking on a...