In recent years, the word “spirituality” is frequently used in a wide range of research areas, such as religion, medical care, nursing, nursing care, clinical psychology, bioethics, education, and business activities. Not only within academic research areas but also within non-academic areas, such as the arena of mass media and medical care practice, nursing and the nursing care practice, this word is being frequently used. Definitions of this term vary as per the userʼs perspective but there are many cases where this word is used to refer to the appearances which were thought of as religion, religiosity, and something being religious or similar. In this paper, I have considered the background of the use of the term “spirituality” in religious research and medical areas, respectively. What is common to both is that the current state of the term “spirituality” is being used to talk about “religious” matters while maintain a distance from the conventional “religion” as an institution. Here we discuss the continuity and discontinuity of “religion” and “spirituality.” If one is conscious of the connection between “religion” and “spirituality,” there should be something that should be derived from the “religion” research to further research on “spirituality” as a concept and as a word. In order to use it as a concept, it is necessary to further examine and train it. The ambiguity of the term “spirituality” has proved useful, and it is also possible to include a wide range of phenomena in the term “spirituality” that could not be included in the concept of “religion”. It is possible to expect further research in this area but at present there are many problems due to ambiguity. Discussions about “spirituality” are expected to gain prominence and in turn, increase the usefulness of this word.