crucial

Adjective

• of the greatest importance
  • the all-important subject of disarmament
    
  • crucial information
    
  • in chess cool nerves are of the essence
    

• having crucial relevance
  • crucial to the case
    
  • relevant testimony
    

• of extreme importance; vital to the resolution of a crisis
  • a crucial moment in his career
    
  • a crucial election
    
  • a crucial issue for women
    

Related words

• Synonyms: 
  all-important(a) , all important(p) , essential , of the essence(p) , important