double distillation
From The Oxford Companion to Spirits & Cocktails
is a common spirits distillation process incorporating two runs through a still (usually a pot still), with the second yielding a distillate that has a significantly higher concentration of ethanol than the first. See also distillate; distillation, process;, ethanol.
This definition is from The Oxford Companion to Spirits & Cocktails, edited by David Wondrich (Editor-in-Chief) and Noah Rothbaum (Associate Editor).