Mead is an alcoholic beverage made from the fermentation of a honey & water mixture. Simple enough, but the breadth of mead is expanded with the use of other fermentable ingredients, non-fermentable additives, and various other techniques.
Mead is sometimes called “honey wine”. This is technically incorrect, as wine involves the fermentation of fruit; however, the alcoholic strength (and taxation) and flavor profile of mead is not dissimilar from wine. Mead should be considered its own category of fermented beverage, a cousin of the more well-known beer & wine.
Some producers flavor white wine with honey and other spices after fermentation; these should not be considered meads. To qualify for the category, honey must undergo fermentation, and must contribute the good majority of the fermentable sugars (the exact amount necessary being debatable).
Mead is sometimes considered to be the most ancient of fermented beverages. The yeast in fermentation convert sugars into alcohol; where wine requires the harvest and/or cultivation of fruit, beer the mashing of grains (typically barley), and sake the conversion of rice starches into sugars, mead is based on honey – a readily available source of immediately fermentable sugar. Readily available to primitive man, who quickly found the effects most enjoyable.