self-assured       
adjective  approving uk/ˌself.əˈʃɔːd/ us/ˌself.əˈʃʊrd/
C2 自信的
having confidence in your own abilities
  The interview showed her as a self-assured and mature student. 面试显示出她是个自信成熟的学生。 
 Synonyms: assertiveconfidentself-assertiveself-confident 
See also: assured (CONFIDENT)