pit zip
n.— «Armpit zippers, affectionately called pit zips, allow you to adjust your body temperature to various wind conditions.» —“Sugoi Vapor Urban Jacket and Conrad Pant” by Chris Cosby Dirt Rag Aug. 7, 2006. (source: Double-Tongued Dictionary)
Further reading
What’s up with ketchup? The shifting history and spelling of the name of this condiment. For centuries, ketchup was a fishy sauce originating in Asia—the tomatoes came only later! Plus, a new book shows what’s lost when a language dies: when there...
Authors often go through several working titles before settling on one. F. Scott Fitzgerald’s The Great Gatsby (Bookshop|Amazon) was originally Trimalchio in West Egg, Trimalchio being an ostentatious nouveau riche character in an ancient Roman work...