What are round timbers placed upright in holes in the ground commonly referred to as?

The term "poles" is commonly used to describe round timbers that are placed upright in holes in the ground. This terminology is often associated with structures such as fences, utility lines, or supports in various construction applications. Poles are generally slender, long, and made from materials like wood, metal, or concrete, providing support or acting as barriers.

Posts, while similar in use, typically refer to larger, sturdier vertical supports that may not always be round and are often used in fencing or structural applications. Pillars and columns, on the other hand, are usually associated with classical architecture and are designed to support loads in buildings, typically being more substantial and often rectangular in shape. Hence, the specific definition and common usage of "poles" align most closely with the description provided in the question.