There are several synonyms for the term "proximal segment". This term is commonly used in anatomical and medical contexts to refer to the portion of a body part that is closest to the center of the body. One common synonym for this term is "upper segment", which is often used to describe the upper portion of an arm or leg. Other synonyms for "proximal segment" include "base segment", "nearest segment", and "initial segment". These terms all refer to the same anatomical structure and can be used interchangeably depending on the context and preference of the speaker or writer.