fierce 是形容词，核心含义和用法如下：

    凶猛的；残暴的；野性的用来形容动物、人或表情具有攻击性、危险性。例：The tiger gave a fierce roar.（老虎发出一声凶猛的吼叫。）例：He has a fierce look on his face.（他脸上带着凶狠的神情。）

    激烈的；猛烈的；白热化的形容竞争、战斗、争论等程度激烈。例：There is fierce competition between the two companies.（这两家公司之间竞争激烈。）例：The storm was so fierce that many trees were blown down.（暴风雨十分猛烈，许多树都被吹倒了。）

    狂热的；强烈的形容情感、欲望等非常强烈。例：She has a fierce desire to succeed.（她有强烈的成功欲望。）例：He is a fierce supporter of the football team.（他是这支足球队的狂热支持者。）