Peripheral fields can be described using a variety of synonyms, depending on the context in which the term is used. One way to describe the periphery is to use the words "marginal" or "fringe", as these words convey the sense of being on the edge or boundary of something. Another synonym for the peripheral fields would be the term "outskirts", which suggests a location that is farther away from the center or core. Additionally, the words "outer", "secondary", or "ancillary" can also be used to describe peripheral fields, as they all imply a sense of something being less important or of secondary importance. Ultimately, the choice of synonym depends on the speaker's intention and the context in which the term is being used.