A cylinder. (This isn't a fake answer.)
A cone
cone
A cone has one circular base and a vertex that is not on the base.as described on math.com
A cone.
cylinder
a cone
A cone has a circular base.
A cylinder. (This isn't a fake answer.)
Cone
A cylinder
A cone is a solid with a flat circular base tapering to its vertex or
A cone
A cone would fit the given description.
a cone.
cone
A prism. A prism is named for its base, eg a triangular prism has a triangle for the base. If the base is a circle, the circular prism is called a cylinder.