well or rail
From The Oxford Companion to Spirits & Cocktails
is the stainless steel rack of liquor bottles kept directly below the bar. It is also known as the “speed well,” since these bottles are easy for the bartender to reach, allowing for quicker drink execution. A “well drink” or “rail drink” is a mixed drink made with an inexpensive, generic liquor (the kind usually used in the well) rather than a named or “call” brand. See call drink. These drinks tend to be cheaper, and some bars offer specials on them to attract and encourage more business. Depending on the establishment, the quality of liquors used in the well may vary widely, with some upscale bars using premium liquors for their well drinks, while dives tend to use generic or value brands.
By: Chad SolomonSee call drink.
This definition is from The Oxford Companion to Spirits & Cocktails, edited by David Wondrich (Editor-in-Chief) and Noah Rothbaum (Associate Editor).