influential       
adjective uk/ˌɪn.fluˈen.ʃəl/ us/ˌɪn.fluˈen.ʃəl/
C1 有影响力的
having a lot of influence on someone or something
  She wanted to work for a bigger and more influential (= powerful) newspaper. 她希望为一家规模更大、更有影响的报纸工作。 
 Johnson was influential (= important) in persuading the producers to put money into the film. 约翰逊在说服制片人投资拍摄此片方面起了重要作用。 
 - More examples
 - He has his own ways of beating the system, making sure that he has good relationships with influential people.
 - He sat under the most influential teacher in his field.
 - He was very influential in shaping the government's economic policy/strategy.
 - Two influential senators have argued for the retention of the unpopular tax.
 - He is regarded as one of the most influential film directors of his generation.