Which term describes a beer that is not filtered, and often contains yeast particles?

The term that describes a beer that is not filtered and often contains yeast particles is "hazy." Hazy beers retain some of the yeast and other particulates that contribute to their opaque appearance, rather than being clear and bright. These characteristics are particularly common in certain styles of beer, such as New England IPAs and wheat beers, where the cloudiness can be a desired aesthetic that boosts flavor perception and mouthfeel.

In contrast, clear beers have been filtered and typically do not contain visible yeast or other particles. Light and dark refer to the color of the beer, which doesn't necessarily indicate whether it has been filtered or contains yeast particles. Therefore, "hazy" is the most accurate term to describe the characteristic of an unfiltered beer with yeast in suspension.