The Collaborative International Dictionary of English v.0.48:

Insight \In"sight`\, n.
   1. A sight or view of the interior of anything; a deep
      inspection or view; introspection; -- frequently used with
      into.
      [1913 Webster]

            He had an insight into almost all the secrets of
            state.                                --Jortin.
      [1913 Webster]

   2. Power of acute observation and deduction; penetration;
      discernment; perception.
      [1913 Webster]

            Quickest insight
            In all things that to greatest actions lead.
                                                  --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

insight
    n 1: clear or deep perception of a situation [syn:
         penetration, insight]
    2: a feeling of understanding [syn: insight, perceptiveness,
       perceptivity]
    3: the clear (and often sudden) understanding of a complex
       situation [syn: insight, brainstorm, brainwave]
    4: grasping the inner nature of things intuitively [syn:
       insight, sixth sense]

Moby Thesaurus II by Grady Ward, 1.0:

79 Moby Thesaurus words for "insight":
   ESP, a priori knowledge, acuity, acumen, acuteness, anschauung,
   anticipation, apperception, appreciation, appreciativeness,
   astuteness, awareness, buddhi, clairsentience, clairvoyance,
   cogency, cognition, cognizance, comprehension, consciousness,
   critical discernment, direct apprehension, discernment,
   extrasensory perception, farseeingness, farsightedness, flair,
   foresight, foresightedness, immediate cognition, incisiveness,
   inspiration, intuition, intuitionism, intuitive reason,
   intuitiveness, intuitivism, judgement, judgment,
   knowledge without thought, longheadedness, longsightedness,
   lucidity, mindfulness, noesis, note, notice, penetration,
   perception, perceptiveness, percipience, perspicaciousness,
   perspicacity, perspicuity, perspicuousness, precognition,
   premonition, providence, psychometry, realization, recognition,
   sagaciousness, sagacity, sageness, sapience, satori, second sight,
   second-sightedness, sensibility, sensitivity, sharpness,
   sixth sense, subconscious knowledge, subconscious perception,
   trenchancy, understanding, unmediated perception, vision, wisdom



The Free On-line Dictionary of Computing (30 December 2018):

INSIGHT

   A simulation and modelling language especially for health
   care problems.

   ["Simulation Modeling with INSIGHT", S.D. Roberts Proc 1983
   Winter Sim Conf, S.D. Roberts et al eds, pp.7-16].

   (1995-03-03)