Circular, adj. see 'Circle'
This seems an inadequate definition of the word. It does no more than point back to a base word without defining the word itself. This is probably true of most entries for adjectives, but in this case that flaw is especially disappointing. "Phenominalogical" is commonly used in a fashion distinct from making reference to the branch of psychology known as phenomenology, as when an observation is labeled "merely phenomenological" for taking only literal phenomena into account, devoid of speculation as to motive or consequence.