derailer

Etymology

derail + -er. Doublet of derailleur.

noun

1. One who, or that which, derails.
   1. (rail transport) Synonym of derail">derail">derail">derail: A device placed on railway tracks in order to cause a train to derail">derail">derail">derail.
2. (cycling, uncommon) Alternative form of derailleur.
   Very few bicycles are of a different color or employ more gears with derailer sprockets and hand brakes. 2009, Louis G. Perez, “Society in the Twenty-First Century”, in The History of Japan (The Greenwood Histories of the Modern Nations), 2nd edition, Westport, Conn., London: Greenwood Press, page 202
   Through sheer ingenuity and resourcefulness, these men handproduced parts such as derailers, stands, seat posts, cranks, fenders, and all manner of elements used in the production of a functional bicycle. 2009, Christine Elliott, David Jablonka, “Cycles Alex Singer”, in Custom Bicycles: A Passionate Pursuit, Images Publishing, page 72, column 2
   Inside, two bearded men are working on a busted fuel pump, and another is repairing a bicycle derailer. 2016, Erik Reece, Utopia Drive: A Road Trip Through America’s Most Radical Idea, New York, N.Y.: Farrar, Straus and Giroux, page 170
   Recent American attempts to further Anglicize the word to “derailer” have met with little success. In any case, no rails are involved.] [2016, Tony Hadland, Hans-Erhard Lessing, Bicycle Design: An Illustrated History, MIT Press, page 246