1.Definition: marked by extreme and violent energy

"Fierce fighting"

Related Adjective(s):ferocious, furious, savage

2.Definition: marked by extreme intensity of emotions or convictions; inclined to react violently; fervid

"Fierce loyalty"

Related Adjective(s):tearing, vehement, violent

3.Definition: ruthless in competition

Related Adjective(s):bowelless, cutthroat

4.Definition: violently agitated and turbulent

"The fierce thunders roar me their music"

Related Adjective(s):boisterous, rough