Definition - What does Intensity mean?
The initial perception of a wine can be noticed by its concentration of color and aroma. If a wine has a dark, deep color, it has intensity. If the wine's aroma are very pronounced, it is also intense. Red wines made with varietals such as Zinfandel, Petit Sirah, Malbec or Petit Verdot for example, have intensity.
WineFrog explains Intensity
"Intensity" is an adjective used more to describe a red wine.
The evaluation of a wine begins with its color, and typically only red wine can have an intensity of color. These are red wines which are opaque or very deep in color. Some are almost inky. They may be an intense ruby red, purple or violet. They do not allow for much light to pass through the wine glass.
By nature, these wines have an intensity in their perfume, as the varietals they are made with have the ability to not only impart a lot of color, but also a lot of fruit characteristics. These varietal wines have the ability to carry the bouquet imparted by oak barrels, thus making them more intense.