occult line

from The Collaborative International Dictionary of English v.0.48
Occult \Oc*cult"\, 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]
    

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