the point of intersection of lines or the point opposite the base of a figure
"The architect marked the vertex where the two roof beams intersected to ensure proper structural alignment."
The highest point, top or apex of something.
"The climber reached the vertex of the mountain just as the sun began to set."
In plain English: A vertex is simply the point where two lines meet to form an angle, often called a corner.
"The highest point on the mountain was marked by a single sharp vertex where three ridges met."
Usage: Use vertex to describe the single highest point on three-dimensional shapes like pyramids and cones, whereas peak is preferred for mountains and two-dimensional figures use apex. Avoid using it interchangeably with tip unless referring specifically to geometric corners where lines meet at a sharp angle.
The word entered Late Middle English from the Latin vertex, which originally meant "top," "crown," or "peak." It is a doublet of the related term vortex.