Actinal is typically used in the field of zoology to describe the oral or ventral side of a radial or bilaterally symmetrical organism, particularly echinoderms. However, there are several synonyms that can be used interchangeably with actinal. One such synonym is "ventral", which refers to the underside or belly of an organism. Another synonym is "oral", which signifies the part of an organism associated with the mouth. Additionally, the term "inferior" can also be utilized as a synonym for actinal, as it describes the lower or bottom side of an organism. These synonyms offer alternative ways to convey the same notion as actinal when discussing the structure or orientation of certain organisms.