Webster's Revised Unabridged Dictionary · 1913

Occult

Occult , adjective

[Latin occultus, past participle of occulere to cover up, hide; ob (see Ob-) + a root prob. akin to English hell: compare French occulte.]

Hidden from the eye or the understanding; invisible; secret; concealed; unknown.
It is of an occult kind, and is so insensible in its advances as to escape observation. — I. Taylor
Collocations (3)
Occult line (Geometry) , 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.

Occult , transitive verb

To eclipse; to hide from sight.