Synonyms for Vehement (same or very similar meaning)
WordNet sense 1 (having strength or power greater than average or expected):
strongWordNet sense 2 (marked by extreme intensity of emotions or convictions; inclined to react violently; fervid):
fierce, trigger-happy, violent, tearingWordNet sense 3 (in an extreme degree):
intenseFrom the ODE community, based on WordNetadd/edit