Cabernet Franc
This red French varietal is widely planted in Bordeaux where it is an important contributor in the blend of many of the region's wines. In most cases Cabernet Franc plays a supporting role, composing approximately 5-20% of the blend, with Cabernet Sauvignon or Merlot taking center stage. Noteworthy exceptions are Saint Emilion's two highest-classified estates (Premier Grand Cru Classe "A"): the famous Chateau Cheval Blanc in which Cabernet Franc is the lead varietal, composing approximately two-thirds of the blend, and the exquisite Chateau Ausone in which Cabernet Franc is blended evenly with Merlot. Outside of France Cabernet Franc is not grown on a wide scale, though it does play an important role for winemakers seeking to emulate the classic Bordeaux style.
DNA testing has revealed Cabernet Franc to be one of the parents (along with Sauvignon Blanc) of Cabernet Sauvignon. The two Cabernet varietals are similar in many respects, though Cabernet Franc tends to be lighter, less tannic and acidic, and more fruity and herbaceous than Cabernet Sauvignon. Cabernet Franc also generally has stronger aromas, often consisting of plum, pepper, or violets.

Cabernet Sauvignon
Descendent from a cross between Cabernet Franc and Sauvignon Blanc, Cabernet Sauvignon quite possibly has become the most commonly planted red wine grape varietal around the globe. It is the leading grape in many of Bordeaux's most acclaimed and famous wines (particularly those of the Haut-Medoc and Graves), and plantings of Cabernet Sauvignon have spread throughout the world in the wake of the excellent Bordeaux style wines it creates. The varietal was instrumental in helping to put New World wines on the map when in 1976 a California Cabernet Sauvignon shockingly won first place over Bordeaux's finest wines during a blind tasting by French judges in the widely-publicized "Judgment of Paris". Today, this varietal is widely planted in its homeland of France, as well as the United States, South America, Australia, South Africa, Eastern Europe, Spain, and Italy (where it has helped create the new "Super Tuscan" class of wines), and can be found in at least some quantity in virtually every wine producing nation on Earth.
Cabernet Sauvignon's flavor and aromas can vary according to the terroir and the physiological ripeness of the fruit at harvest time, but it is typically characterized by dark fruits like cassis, plums, and black cherries, as well as mint, eucalyptus, cedar, and tobacco. A bell pepper quality can also be apparent, particularly in cool climates that produce slightly under-ripe fruit. Cabernet Sauvignon is also a varietal that is quite tannic, disposing the wines made from it to significant aging; many versions require 10 years or more before reaching their peak period of flavor and balance.

Carmenere (car-men-yehr)

Belonging to the Cabernet family, Carmenere is one of Bordeaux's six permitted varietals for red wine blends, but is now typically used only in small amounts, if at all, by the winemakers of that region. During the phylloxera infestation of the mid-1800s, Carmenere vines were hit especially hard and the varietal was thought to have been almost wiped out. As the vineyards of Bordeaux were replanted, Carmenere was largely forsaken in favor of varietals that produced more consistent yields and were less prone to disease. Luckily for Carmenere, over the years it has enjoyed the good fortune of being mistaken for both Merlot and Cabernet Franc, leading to its unintentional importation to other countries. This occurred in Italy, New Zealand, and most notably in Chile, where cuttings believed to be Merlot were imported and widely planted prior to the Bordeaux phylloxera outbreak of the mid-1800s. Only in the 1990s were these "Merlot" vines discovered to be, in fact, Carmenere. Chile is now the largest producer of Carmenere wines worldwide, and the grape is used both in blends as well as pure varietal wines, the latter being quite a departure from its traditional role in Bordeaux. The warmer and drier climate of Chile is much more favorable to the healthy growth and production of Carmenere, which at its best produces wines replete with flavors of red fruits, earth, smoke, and spice. It tends to be medium-bodied and softer than Cabernet Sauvignon. Happily, Carmenere appears to be undergoing resurgence as vineyards in California, Washington State, and Australia are beginning to plant the varietal in increasing numbers.

Cepage
This is a French word with a meaning equivalent to "grape varietal" in English. It also is used to refer to a wine's blend. For instance, a common Bordeaux cepage might include Cabernet Sauvignon, Merlot, Cabernet Franc, and Petit Verdot.

Chardonnay

One of the world's most popular and widely-planted white wine grape varietals, Chardonnay is quite hardy and relatively easy to cultivate. It is also considerably influenced by the terroir of the region in which it is grown; thus, it is responsible for white wines with quite varied characteristics. These can include a flinty mineral quality (as with Chablis), a buttery, oaky flavor (as with Meursault and many Californian examples), and notes of exotic fruits (as with many wines from Australia and other New World locales). In its ancestral home of France, Chardonnay is most famous for the world-renowned white wines of Burgundy. It is also a major contributor to the sparkling wines of Champagne, which are typically a blend of Chardonnay and Pinot Noir or Pinot Meunier. For Champagne made entirely with white wine grapes, known as blanc-de-blanc Champagne, Chardonnay is typically the only varietal used. In California, Chardonnay is the state's most important white wine grape with almost one hundred thousand acres planted as of this writing. Chardonnay continues to grow in popularity worldwide, with plantings increasing in Australia, New Zealand, Italy, and South America.

Claret
This term has no specific legal definition and is not consistently used to mean the same thing. The most common definition, popular in Britain, is as a synonym for red Bordeaux wine. Sometimes the word is used to refer to wines from outside Bordeaux that are of a similar style. In other contexts, it is used to refer to pale, dry red wines.

Clean
Fresh. A wine without noticeable flaws in appearance, aroma or flavor.

Clos (France)
Meaning "enclosed" or "fenced" in French, the term refers to a walled vineyard although on wine labels the term is used liberally.

Closed
Tasting lingo describing an undeveloped wine, a wine with little flavor or aroma - a wine without character. The term is often applied to young Bordeaux or Cabernet Sauvignons that have "closed down" but are destined to become "big" reds with maturity.

Coarse
A wine that tastes harsh or crude.