What term is used to describe very clear cask ale?

The term that accurately describes very clear cask ale is "Brilliant." This term refers to the visual clarity of the beer, indicating that it has been well-conditioned and has settled properly, resulting in minimal haze and excellent transparency. A brilliant cask ale often showcases the beer's color and carbonation without any turbidity, reflecting a high level of craftsmanship in the cask conditioning and serving process.

While "Polished" might suggest a refined or smooth character, it is not a standard term used to specifically denote clarity in cask ale. Cask Cleared is not a recognized term within the brewing lexicon and doesn't specifically refer to clarity. Filtered ale, although it implies clarity achieved through filtration, refers more broadly to the method rather than the condition of the cask ale itself. In summary, "Brilliant" is the accepted terminology used to describe cask ale that is exceptionally clear, highlighting its quality and presentation.