A pickleback is a type of shot wherein a shot of whiskey is chased by a shot of pickle brine. The pickle brine works to neutralize both the taste of the whiskey and the burn of the alcohol. The Pickleback is sometimes also called a Piskey.
While the origins of a pickle brine chaser are unknown, the term "Pickleback" was introduced to the patrons of The Bushwick Country Club bar in Williamsburg, Brooklyn by Reggie Cunningham in 2006. Also the name of a facebook petition to see if a Pickle could gain more fans than Nickelback. 
The drink, as described, has since become commonplace in many Brooklyn bars.
The "pickleback" has since spread from Brooklyn to Europe, with many elite bars now offering picklebacks on their menu. The drink has had significant success in Aberdeen, Scotland thanks to their reputed popularity amongst staff of the craft brewer BrewDog whose Flagship bar is in the city. This has resulted in city establishment "The Tippling House" having to increase their nightly supply of pickle brine to ensure that the drink can stay available. 
- Cecchini, Toby. Case Study: Got Your Pickleback. http://tmagazine.blogs.nytimes.com/2010/03/16/case-study-got-your-pickleback/, 2010
- Pease, Victoria. The Tippling House shakes up the perfect intimate cocktail bar. http://local.stv.tv/aberdeen/news/going-out/220554-cocktail-bar-the-tippling-house-on-belmont-street-is-a-success/, 2013
-  - 5 Best bars for Pickleback shots