Pyramidalize is a term that refers to the shape of a pyramid, or something that is arranged or constructed in a pyramid shape. However, there are several other synonyms to use instead of this word. "Build up" is a simple yet precise synonym and can be used for situations where things are arranged in an upwards manner. "Stack" works well for objects that are placed in a pile or column, while "conicalize" is an ideal term for something that is shaped like a cone. "Triangulate" could be the best term to use if something is being structured with triangular shapes. Finally, "taper" works well to describe something that narrows gradually toward its point.