It's rare in the booze world for a category to be defined by purpose rather than production, as amaro is, but it's this fact that really speaks to the magic of it. Devilishly difficult to pin down, an amaro is, broadly speaking, a bittersweet herbal liqueur. The word amaro is Italian for "bitter" and the best known examples of the category hail from mainland Italy and Sicily.
Italy is a nation steeped in history and tradition, much of which is based around the twin pillars of eating and drinking. The rules are simple: an aperitivo before dinner, wine during, and a glass of amaro afterwards to seal the deal.