pugnacity

from WordNet (r) 3.0 (2006)

pugnacity
    n 1: a natural disposition to be hostile [syn: {aggressiveness},
         {belligerence}, {pugnacity}]

from The Collaborative International Dictionary of English v.0.48

Pugnacity \Pug*nac"i*ty\, n. [L. pugnacitas: cf. F.
   pugnacit['e].]
   Inclination or readiness to fight; quarrelsomeness. " A
   national pugnacity of character." --Motley.
   [1913 Webster]