Meaning

adjective hidden and difficult to see

adjective having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding

originEtymology tree Proto-Indo-European *h₁ep-der. Proto-Indo-European *h₁épsder. Proto-Indo-European *h₁óp(i) Proto-Italic *op Latin ob Latin ob- Proto-Indo-European *ḱel- Proto-Indo-European *ḱéletider. Latin *celo Latin occulō Latin occultusbor. English occult English -er English occulter From occult + -er.

Etymology from Wiktionary, CC BY-SA 3.0