Noun
A convex molding of rounded surface, generally from half to three quarters of a circle.
A round molding encircling a cannon near the mouth.
Source: Webster's dictionaryBelow their caps, an astragal molding encircles the column like a ring. Source: Internet
Unlike the Doric and Ionic column capitals, a Corinthian capital has no neck beneath it, just a ring-like astragal molding or a banding that forms the base of the capital, recalling the base of the legendary basket. Source: Internet