bashful       
adjective uk/ˈbæʃ.fəl/ us/ˈbæʃ.fəl/
 害羞的,羞怯的
often feeling uncomfortable with other people and easily embarrassed
  She gave a bashful smile as he complimented her on her work. 当他恭维她的工作成果时,她腼腆地笑了笑。 
 Synonyms: coy (MODEST)modest (QUIETLY SUCCESSFUL) reserved (PERSON)reticent retiring (SHY) self-effacingshy (NERVOUS)timidunassuming