giggling gear
other.— «“Giggling Gear”—This is a term used in playing a joke on an apprentice who will be sent to the stock room ostensibly to get a part for a machine [sic] being instructed to ask for a “giggling gear,” there being no such thing,and the laugh that the jokers get out of it gives the first part of the term “giggling.”» —“Trade Jargon—Carpet Industry” by Ellis H. Custer in Westchester and Yonkers, N.Y. Lexicon of Trade Jargon Mar. 23, 1938. (source: Double-Tongued Dictionary)