The Collaborative International Dictionary of English v.0.48:

Interest \In"ter*est\, v. t. [imp. & p. p. Interested; p. pr.
   & vb. n. Interesting.] [From interess'd, p. p. of the older
   form interess, fr. F. int['e]resser, L. interesse. See
   Interest, n.]
   [1913 Webster]
   1. To engage the attention of; to awaken interest in; to
      excite emotion or passion in, in behalf of a person or
      thing; as, the subject did not interest him; to interest
      one in charitable work.
      [1913 Webster]

            To love our native country . . . to be interested in
            its concerns is natural to all men.   --Dryden.
      [1913 Webster]

            A goddess who used to interest herself in marriages.
                                                  --Addison.
      [1913 Webster]

   2. To be concerned with or engaged in; to affect; to concern;
      to excite; -- often used impersonally. [Obs.]
      [1913 Webster]

            Or rather, gracious sir,
            Create me to this glory, since my cause
            Doth interest this fair quarrel.      --Ford.
      [1913 Webster]

   3. To cause or permit to share. [Obs.]
      [1913 Webster]

            The mystical communion of all faithful men is such
            as maketh every one to be interested in those
            precious blessings which any one of them receiveth
            at God's hands.                       --Hooker.

   Syn: To concern; excite; attract; entertain; engage; occupy;
        hold.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Interesting \In"ter*est*ing\, a.
   Engaging the attention; exciting, or adapted to excite,
   interest, curiosity, or emotion; as, an interesting story;
   interesting news. --Cowper.
   [1913 Webster]

WordNet (r) 3.0 (2006):

interesting
    adj 1: arousing or holding the attention [ant: uninteresting]

Moby Thesaurus II by Grady Ward, 1.0:

71 Moby Thesaurus words for "interesting":
   absorbing, alluring, appealing, appetizing, attractive, beguiling,
   bewitching, blandishing, cajoling, captivating, catching,
   charismatic, charming, coaxing, come-hither, compelling,
   coquettish, enchanting, engaging, engrossing, enravishing,
   enthralling, enticing, entrancing, exciting, exotic, fascinating,
   fetching, flirtatious, glamorous, gripping, hypnotic, intriguing,
   inviting, irresistible, juicy, lively, mesmeric, mouth-watering,
   piquant, prepossessing, provocative, provoking, provoquant, racy,
   ravishing, readable, rich, riveting, seducing, seductive, siren,
   sirenic, spellbinding, spellful, spicy, stimulating, succulent,
   taking, tantalizing, teasing, tempting, thought-challenging,
   thought-inspiring, thought-provoking, tickling, titillating,
   titillative, winning, winsome, witching



The Jargon File (version 4.4.7, 29 Dec 2003):

interesting
 adj.

    In hacker parlance, this word has strong connotations of ?annoying?, or
    ?difficult?, or both. Hackers relish a challenge, and enjoy wringing all
    the irony possible out of the ancient Chinese curse ?May you live in
    interesting times?. Oppose trivial, uninteresting.


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

interesting

   In hacker parlance, this word has strong connotations of
   "annoying", or "difficult", or both.  Hackers relish a
   challenge, and enjoy wringing all the irony possible out of
   the ancient Chinese curse "May you live in interesting times".

   [Jargon File]