A companion of sorts to ‘mouthfeel,’ the ‘body’ of a wine refers to how light or heavy it sits in your mouth.
You’ll often hear wines referred to as ‘light-bodied’ or ‘full-bodied’ — and in general, you can expect whites to exhibit the former and reds the latter. That being said, there’s a spectrum within each category — so certain white wines (like barrel-fermented sauvignon blanc or oaked chardonnay) can be full-bodied, and certain reds (like Willamette Valley pinot noir and the French grape gamay) can be lighter bodied.
Like mouthfeel, body can be influenced by a number of factors including the natural characteristics of the varietal, winemaking techniques, and alcohol level. The higher the alcohol, for example, the more viscous, heavy, and ‘full-bodied’ a wine will be.