backlash

Etymology

From back + lash.

noun

1. (literally) A suddenly reversed or backward motion, such as of a rope or elastic band when it snaps under tension.
2. (figurative) A negative reaction, objection or outcry, especially of a violent or abrupt nature.
   The public backlash to the proposal was quick and insistent.
3. (mechanics) The looseness through which one part of connected machinery, such as a wheel, gear, piston, or screw, can be moved without moving the connected parts, or a measurement of the distance moved thereby; either intentional (as allowance) or unintentional (from error or wear).
   ... the word "backlash" is used in the extended sense in which it is understood in Lancashire and Yorkshire , including not only backlash proper , but also break of contact between the working faces of the teeth of the two wheels when the driven wheel overruns the driver without actual backlash . To place rope or belt drums of any considerable size upon shafts driven by spur gearing is nearly always dangerous. 1896 Mr. Michael Longridge, of Manchester: Breakdowns of Stationary Steam-Engines. Proceedings. Institution of Mechanical Engineers. Page 541
4. (mechanics) The jarring or reflex motion caused in badly fitting machinery by irregularities in velocity or a reverse of motion.
   In ...breakages from high speed and irregular pitch, ten out of the eleven wheels had spur segments moulded from patterns, instead of by machinery; and in three of the ten the teeth were cast upon the felks, and were twisted and drawn, as they generally are when cast in this way, by the contraction of the mass of metal of which they form a part. In every instance the speed was high, and in several cases there was more or less backlash or over-running. 1896 Mr. Michael Longridge, of Manchester: Breakdowns of Stationary Steam-Engines. Proceedings. Institution of Mechanical Engineers. Page 54

verb

1. To perform a backlash, to lash back in reaction to some cause.
   1894 William Westall. Tinkler. Ludgate Illustrated Magazine. Vol VIII Thrutch factory was a queer old concern. It had been built piecemeal-here a bit and there a bit. There were a new end and an old end, the spinning-rooms in the one being light and lofty, in the other low. and gloomy. Looms were shoved in everywhere. There were a "long shop" with three hundred, a "top shop" with a hundred, a "back shop" with fifty-three, and a "little shop" with fifteen. Never was its equal for gearing. Shafts were everywhere inside and out, overground and underground, climbing snake-like up the walls, and boring into the roofs; spurwheels, great and small, whirled, clashed and "backlashed" all over the place.
   Just as it began to get dusk and the shadows from the trees deepening the twilight that had already spread over the lake, giving a peculiarly lonesome effect that water always has upon the approach of night, Uncle succeeded in getting out the longest cast he had yet made — about seventy-five feet. Unfortunately, or perhaps I should say fortunately, his reel over-ran and backlashed for him. Patiently he set about untangling his line; I resting the oars and holding the boat stationary. 1895 W. C. Kepler. Uncle and the Bass The American Angler - Volume 25 - Page 226
   1909 La Compagnie Générale Transatlantique v. Hayes. (Circuit Court of Appeals, Second Circuit. March 16, 1909.) No. 205. There was testimony that but for the orders of these men, or one of them, the case would have been properly backlashed before being lowered into the hold and that the anxiety of the foreman to get the cargo in quickly induced him to order this case sent down without being properly safeguarded.
   May 2, 1922, locomotive 2469 , Hornell, N. Y. Screw reverse gear backlashed due to latch spring too weak to hold it in place ; 1 injured 1922 Interstate Commerce Commission. Fifth Annual Report. Chief Inspector of Locomotive Boilers. Annual Report of the Chief Inspector. Bureau of Locomotive Inspection. To the Interstate Commerce Commission
   I have the faculty of getting more backlashed in less casts with more kinds of guaranteed anti-backlash reels than any man who reads this sad confession. I am letter-perfect at it. Yet I do sometimes catch fish. 1936 Gifford Pinchot. Two's Company. The Rotarian April 1936