You're probably thinking of a cone. There is some disagreement as to whether the point of a cone qualifies as a vertex.
This figure is a CONE.
cone
A right cylindrical cone has a circle for a base and one vertex. a diagram is shown on unitmath.com
A cone
Because the base of a cone is round, it is the only three dimensional figure with only one vertex.
A cone.
A circle could be, and I think that an ellipse also could be.
The line or plane upon which a geometric figure is thought of as resting is called the base. A three-dimensional figure with a circular base and the top meeting at a vertex; it resembles a funnel cone.
trapezoid
A polyhedron is a three-dimensional figure formed by flat surfaces that are bounded by polygons joining along their sides (the faces of the polyhedron).A circle is not a polygon, but we can say that a circle is the limit of a regular polygon with n sides. It means that if n becomes larger and larger, the polygon shape approaches to a circle. A circle is a two dimensional figure as a polygon is, but a three dimensional figure whose base(s) is/are a circle cannot be called a polyhedron.
You're probably thinking of a cone. There is some disagreement as to whether the point of a cone qualifies as a vertex.
A cone.
This figure is a CONE.
cone
A spitial figure with a circular bases no edges and one vertex
A right cylindrical cone has a circle for a base and one vertex. a diagram is shown on unitmath.com