Merriam-Webster's Collegiate® Dictionary, 11th Edition
OCCULT
I. transitive verb
Etymology: Latin occultare, frequentative of occulere
Date: 1500
to shut off from view or exposure ; cover , eclipse , occulter noun
II. adjective see: ob-
Date: 1533
not revealed ; secret , not easily apprehended or understood ; abstruse , mysterious , hidden from view ; concealed, of or relating to the occult, not manifest or detectable by clinical methods alone , occultly adverb
III. noun
Date: 1923
matters regarded as involving the action or influence of supernatural or supernormal powers or some secret knowledge of them