Hidden mean that which is secret, hidden, unseen.
Hidden is an adjective of Latin origin, "occultu", which is everything that is covered, that is mysterious.
In philosophy, the word occult refers to causes that cannot be known in themselves and are only revealed in consequence of the effects they cause.
Occult sciences are sciences whose knowledge and practices are shrouded in mystery. Ex: astrology, magic, alchemy, kabbalah etc.
The word apocryphal is a qualifying adjective, of Greek origin, which means hidden, one that has not been explored. Likewise, the word arcane, is an adjective that also means hidden, secret, kabbalistic. It is each of the cards in the tarot deck that represents what is hidden, what is mysterious.
For many cultures, the owl is an animal that represents the powerful connoisseur of the occult, as it has habits night, standing wide-eyed in the dark, and always being alert to movements and noises nightly.
Hidden friend, also called secret friend, is a game, which is performed at Christmas, where the participants make a secret draw among themselves and exchange gifts, not knowing who drew them or what they will. receive.