fierce

marked by extreme and violent energy

• “a ferocious beating”
• “fierce fighting”
• “a furious battle”

marked by extreme intensity of emotions or convictions; inclined to react violently; fervid

• “fierce loyalty”
• “in a tearing rage”
• “vehement dislike”
• “violent passions”

ruthless in competition

• “cutthroat competition”
• “bowelless readiness to take advantage”

violently agitated and turbulent

• “boisterous winds and waves”
• “the fierce thunders roar me their music” Ezra Pound
• “rough weather”
• “rough seas”