In medieval Japan, kami-worship was generally seen as being part of Japanese Buddhism, with the kami themselves often interpreted as Buddhas. At this point, the term "Shinto" increasingly referred to "the authority, power, or activity of a "kami", being a "kami", or, in short, the state or attributes of a "kami"." It appears in this form in texts such as "Nakatomi no harai kunge" and "Shintōshū" tales. In the "Japanese Portuguese Dictionary" of 1603, "Shinto" is defined as referring to ""kami" or matters pertaining to "kami"." The term "Shinto" became common in the 15th century. During the late Edo period, the kokugaku scholars began using the term "Shinto" to describe what they believed was an ancient, enduring and indigenous Japanese tradition that predated Buddhism; they argued that "Shinto" should be used to distinguish kami worship from traditions like Buddhism, Taoism, and Confucianism. This use of the term "Shinto" became increasingly popular from the 18th century. The term "Shinto" has been commonly used only since the early 20th century, when it superseded the term "taikyō" ('great religion') as the name for the Japanese state religion.