The Collaborative International Dictionary of English v.0.48:

Quarrelsome \Quar"rel*some\, a.
   Apt or disposed to quarrel; given to brawls and contention;
   easily irritated or provoked to contest; irascible; choleric.
   [1913 Webster]

   Syn: Pugnacious; irritable; irascible; brawling; choleric;
        fiery; petulant.
        [1913 Webster] -- Quar"rel*some*ly, adv. --
        Quar"rel*some*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

quarrelsome
    adj 1: given to quarreling; "arguing children"; "quarrelsome
           when drinking"

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "quarrelsome":
   acrid, adverse, aggressive, antagonistic, antipathetic, argumental,
   argumentative, battling, bellicose, belligerent, bickering, bitter,
   bloodthirsty, bloody, bloody-minded, brawling, cankered,
   cat-and-dog, cat-and-doggish, caustic, chauvinist, chauvinistic,
   choleric, clashing, colliding, combative, conflicting, contending,
   contentious, contestant, contesting, contrary, controversial,
   counter, crabbed, cranky, cross, despiteful, dialectic,
   disagreeable, disputant, disputatious, dissentient, dissentious,
   dissident, divisive, dyspeptic, enemy, eristic, factional,
   factious, ferocious, fierce, fighting, fractious, full of fight,
   full of hate, grouchy, hateful, hawkish, hostile, ill-humored,
   inimical, irascible, irritable, jingo, jingoish, jingoist,
   jingoistic, litigious, logomachic, malevolent, malicious,
   malignant, martial, militant, militaristic, military, offensive,
   partisan, peevish, petulant, pilpulistic, polarizing, polemic,
   pro and con, pugnacious, querulous, rancorous, repugnant,
   saber-rattling, sanguinary, sanguineous, savage, scrappy,
   set against, shrewish, soldierlike, soldierly, sore, spiteful,
   squabbling, striving, struggling, testy, trigger-happy, truculent,
   unfriendly, unpacific, unpeaceable, unpeaceful, venomous, virulent,
   vitriolic, warlike, warmongering, warring, wrangling