Fetching details from the dictionary...
fierce (fight, competition, etc.); severe; hot; hard; bitter; keen; cutthroat
スポーツ業界のトップを巡る争いは熾烈だ。
The competition to reach the top of the sports world is fierce.
採用試験は熾烈な争いで、倍率が百倍を超えた。
The hiring exam was a cutthroat competition, with over a hundred applicants per spot.
熾烈な批判にさらされながらも彼は信念を曲げなかった。
Even under fierce criticism, he never wavered in his convictions.