excerpt from http://www.npr.org/blogs/npr-history-dept/2015/04/23/401681334/7-lost-american-slang-words
Dingus, 1890s. A nebulous, unspecified object.
Example: Nineteenth century slang may have crescendoed in the 1890s with this report on a new game: Tiddledywinks. "You take a wink, put it on the dingus, press a tiddledy on the wink and make it jump into the winkpot. ... If you succeed, you are entitled to a difficiety and for every wink you jump into the dingpot, from the duwink you count a flictiddledy and you keep on operating the tinkwinkle upon the pollywog until the points so carried equal the sum total of the bogwip multiplied by the putertinktum and added to the contents of the winkpot or words to that effect and you have won the game." From the Tribune in McCook, Neb., on April 24, 1891. And, while writing about operating a coal stove, a Wisconsin person noted this in the Appeal in Memphis, Tenn., on Dec. 28, 1873: "We turned every dingus in the stove that was movable."