a. [ L. occultus, p. p. of occulere to cover up, hide; ob (see Ob-) + a root prob. akin to E. hell: cf. F. occulte. ] Hidden from the eye or the understanding; invisible; secret; concealed; unknown. [ 1913 Webster ]

It is of an occult kind, and is so insensible in its advances as to escape observation. I. Taylor. [ 1913 Webster ]

Occult line (Geom.), a line drawn as a part of the construction of a figure or problem, but not to appear in the finished plan. --
Occult qualities, those qualities whose effects only were observed, but the nature and relations of whose productive agencies were undetermined; -- so called by the schoolmen. --
Occult sciences, those sciences of the Middle Ages which related to the supposed action or influence of occult qualities, or supernatural powers, as alchemy, magic, necromancy, and astrology. [ 1913 Webster ]

v. t. To eclipse; to hide from sight. [ 1913 Webster ]

n. [ L. occultatio a hiding, fr. occultare, v. intens. of occulere: cf. F. occultation. See Occult. ] 1. (Astron.) The hiding of a heavenly body from sight by the intervention of some other of the heavenly bodies; -- applied especially to eclipses of stars and planets by the moon, and to the eclipses of satellites of planets by their primaries. [ 1913 Webster ]

2. (Fig.:) The state of being occult. [ 1913 Webster ]

The reappearance of such an author after those long periods of occultation. Jeffrey. [ 1913 Webster ]

Circle of perpetual occultation. See under Circle. [ 1913 Webster ]

a. 1. Hidden; secret. [ Obs. ] Shak. [ 1913 Webster ]

2. (Astron.) Concealed by the intervention of some other heavenly body, as a star by the moon. [ 1913 Webster ]

n. Same as Occultation. [ 1913 Webster ]

n. 1. A certain Oriental system of theosophy. A. P. Sinnett. [ 1913 Webster ]

2. Belief in occult powers or in supernatural forces other than the God of traditional religions, such as in magic, necromancy, alchemy, and astrology. [ PJC ]

3. The study and alleged use of supernatural agencies as in magic, astrology, witchcraft, alchemy, necromancy, spiritualism (communication with the dead), and fortune-telling. [ PJC ]

n. An adherent of occultism. [ 1913 Webster ]

adv. In an occult manner. [ 1913 Webster ]

n. State or quality of being occult. [ 1913 Webster ]