The DICT Development Group

  Gnostic \Gnos"tic\, a.
     1. Knowing; wise; shrewd. [Old Slang]
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              I said you were a gnostic fellow.     --Sir W.
                                                    Scott.
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     2. (Eccl. Hist.) Of or pertaining to Gnosticism or its
        adherents; as, the Gnostic heresy.
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  Gnostic \Gnos"tic\, n. [L. gnosticus, Gr. ? good at knowing,
     sagacious; as a n., man that claims to have a deeper wisdom,
     fr. gignw`skein to know: cf. F. gnostique. See Know.]
     (Eccl. Hist.)
     One of the so-called philosophers in the first ages of
     Christianity, who claimed a true philosophical interpretation
     of the Christian religion. Their system combined Oriental
     theology and Greek philosophy with the doctrines of
     Christianity. They held that all natures, intelligible,
     intellectual, and material, are derived from the Deity by
     successive emanations, which they called Eons.
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  Gnostic
       adj 1: of or relating to Gnosticism; "Gnostic writings"
       2: possessing intellectual or esoteric knowledge of spiritual
          things [ant: agnostic]
       n : an advocate of gnosticism