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]

The Free On-line Dictionary of Computing (19 January 2023):

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]


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.