The Collaborative International Dictionary of English v.0.48:

Harass \Har"ass\ (h[a^]r"as or h[.a]*r[a^]s"), v. t. [imp. & p.
   p. Harassed (h[a^]r"ast or h[.a]*r[a^]st"); p. pr. & vb. n.
   Harassing.] [F. harasser; cf. OF. harace a basket made of
   cords, harace, harasse,a very heavy and large shield; or
   harer to set (a dog) on.]
   To fatigue; to tire with repeated and exhausting efforts;
   esp., to weary by importunity, teasing, or fretting; to cause
   to endure excessive burdens or anxieties; -- sometimes
   followed by out.
   [1913 Webster]

         [Troops] harassed with a long and wearisome march.
                                                  --Bacon.
   [1913 Webster]

         Nature oppressed and harass'd out with care. --Addison.
   [1913 Webster]

         Vext with lawyers and harass'd with debt. --Tennyson.

   Syn: To weary; jade; tire; perplex; distress; tease; worry;
        disquiet; chafe; gall; annoy; irritate; plague; vex;
        molest; trouble; disturb; torment.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

harassed \harassed\ (h[a^]r"ast or h[.a]*r[a^]st"), adj.
   troubled persistently, especially with petty annoyances; as,
   harassed working mothers.

   Syn: annoyed, harried, pestered.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

harassed
    adj 1: troubled persistently especially with petty annoyances;
           "harassed working mothers"; "a harried expression"; "her
           poor pestered father had to endure her constant
           interruptions"; "the vexed parents of an unruly teenager"
           [syn: annoyed, harassed, harried, pestered,
           vexed]

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "harassed":
   annoyed, anxious, badgered, baited, bedeviled, beset, bothered,
   bugged, bullyragged, chivied, deviled, distracted, distrait,
   distressed, dogged, embarrassed, fretted, harried, haunted,
   heckled, hectored, hounded, inconvenienced, irked, needled,
   nipped at, persecuted, perturbed, pestered, picked on, plagued,
   put to it, puzzled, ragged, sore beset, teased, tormented,
   troubled, vexed, worried, worried sick, worried stiff