Monolithic column

A monolithic column or "single-piece column" is a large column of which the shaft is made from a single piece of stone instead of in vertical sections. Smaller columns are very often made from single pieces of stone, but are less often described as monolithic, as the term is normally reserved for the much less common very large column made in this way. Choosing to use monolithic columns produces considerable extra difficulties in quarrying and transport, and may be seen as a statement of grandeur and importance in a building. In modern architecture using concrete the situation is different, and the term is less likely to be used in this context.

Monolithic columns are characteristic of Ancient Egyptian temples, and the examples in the portico of the Pantheon in Rome were also transported from Egypt.

...
Wikipedia