cut-throat
adjective /ˈkʌt θrəʊt/
  /ˈkʌt θrəʊt/
 [usually before noun]- (of an activity) in which people compete with each other in aggressive and unfair ways
- the cut-throat world of politics
 
Oxford Collocations DictionaryCut-throat is used with these nouns:- competition
 - razor
 - world
 - …