Source : Webster's Revised Unabridged Dictionary (1913)

Irksome \Irk"some\, a.
   1. Wearisome; tedious; disagreeable or troublesome by reason
      of long continuance or repetition; as, irksome hours;
      irksome tasks.

            For not to irksome toil, but to delight, He made us.
                                                  --Milton.

   2. Weary; vexed; uneasy. [Obs.]

            Let us therefore learn not to be irksome when God
            layeth his cross upon us.             --Latimer.

   Syn: Wearisome; tedious; tiresome; vexatious; burdensome.

   Usage: {Irksome}, {Wearisome}, {Tedious}. These epithets
          describe things which give pain or disgust. Irksome is
          applied to something which disgusts by its nature or
          quality; as, an irksome task. Wearisome denotes that
          which wearies or wears us out by severe labor; as,
          wearisome employment. Tedious is applied to something
          which tires us out by the length of time occupied in
          its performance; as, a tedious speech.

                Wearisome nights are appointed to me. --Job vii.
                                                  3.

                Pity only on fresh objects stays, But with the
                tedious sight of woes decays.     --Dryden.
          -- {Irk"some*ly}, adv. -- {Irk"some*ness}, n.

Source : WordNet®

irksome
     adj : so lacking in interest as to cause mental weariness; "a
           boring evening with uninteresting people"; "the
           deadening effect of some routine tasks"; "a dull play";
           "his competent but dull performance"; "a ho-hum speaker
           who couldn't capture their attention"; "what an irksome
           task the writing of long letters is"- Edmund Burke;
           "tedious days on the train"; "the tiresome chirping of
           a cricket"- Mark Twain; "other people's dreams are
           dreadfully wearisome" [syn: {boring}, {deadening}, {dull},
            {ho-hum}, {slow}, {tedious}, {tiresome}, {wearisome}]