It’s from the Latin “numen” meaning a nod or beckoning, particularly the nod of the Gods of ancient myth. It was rediscovered and brought into western thinking by the German Philosopher/Theologian Rudolf Otto in his book “The Holy” (“Das Heilige”) first published in 1917.
Otto began a shift away from the rationalism and speculative side of the enlightenment and more toward an “irrational” side of religious understanding; a sense of “power” and “mystery” and a sense of the “living God” (following a lead by Luther).
The numinous is the wholly other; the “mysterium tremendum” and the “mysterium fascinans.”
The numinous (sacred) is “saturated with being and power.” Life is full of the manifestation of the sacred (“hierophanies”) intersecting into our lives.
C.S. Lewis knew of it and discussed it widely; his books have literally taken off as religious bestsellers 50 years after his death.
Sooooooo. . .what has (or who) intersected into your life and do you wish to share?