cutthroat
adjective mainly UK uk/ˈkʌt.θrəʊt/ us/ˈkʌt.θroʊt/
激烈的;残酷无情的;不择手段的
not involving considering or worrying about any harm caused to others
the cutthroat world of journalism 竞争激烈的新闻界
The advertising world can be a very cutthroat business. 广告行业的竞争会相当残酷。
Synonym: fierce