"Somatic" is an application of the Greek word "soma" which refers to the entire body as the place where being human occurs. The idea that "mind" and "body" are separate, for instance, is a powerful way to look at experience, and very influential in culture, but not literally true.
As an archetypal image, "soma/tic" referes to a complex, a nexus of experience, narratives, meaning, and behavior oriented around a specific principle shared by human beings. Every-body. "Soma" makes "Body" central to understanding humanity, a lens through which to color, include, organize other ideas associated with human embodiment like mind, spirit, soul, physique, and connect with other creatures through embodiment.