Synonyms for Pugnacious (same or very similar meaning)
WordNet sense 1 (tough and callous by virtue of experience):
hard-bitten, hard-boiledWordNet sense 2 (ready and able to resort to force or violence):
roughWordNet sense 3 (having or showing determination and energetic pursuit of your ends):
aggressiveFrom the ODE community, based on WordNetadd/edit