ferocious
adjective
fəˈrəʊʃəs 
fəˈroʊʃəs very aggressive or violent; very strong
Synonym
savagea ferocious beast/attack/storma man driven by ferocious determinationferocious opposition to the planferociously fəˈrəʊʃəsli fəˈroʊʃəsli 
Definition of ferocious adjective from the Oxford Advanced Learner's Dictionary
fəˈrəʊʃəs fəˈroʊʃəs fəˈrəʊʃəsli fəˈroʊʃəsli 