The term "numinous" can be used as either an adjective or a noun. As an adjective, it describes anything having a spiritual or mystical quality, provoking feelings of wonder and awe. As a noun, "The Numinous" can refer to this feeling, or to that which causes it. It is inherently a rather indefinite concept, since it refers to the feeling humans may have of confronting things felt to be beyond rational comprehension. A sense of one's relationship to the numinous can be seen as a foundation for much spiritual or religious feeling.

This term was defined by Rudolf Otto in his influential 1917 book, The Idea of the Holy.