As a sociological term from the Muromachi period to the Edo period, ikki referred to military forces that had not been officially recognized by the central government or the local government; such forces included monk-soldiers (known in Edo period as sohei, meaning "armed priests"), who the shrine authorities used to submit claims such as a goso (a petition lodged directly with the Imperial Court or the shogunate government).
室町時代から江戸初期までの社会用語としては、神社勢力が強訴などの要求を行うための武力である僧衆（江戸時代に僧兵と呼ばれる）も含め、中央もしくは地方政権から非公認の武装勢力そのものを指した。