opaquely       
adverb  formal uk/əʊˈpeɪk.li/ us/oʊˈpeɪk.li/
 难以理解地
in a way that is difficult to understand
  Her eyes were opaquely sad. 她的眼睛透着难以名状的悲伤。 
 "I would be honoured," he said, while smiling opaquely. “我很荣幸”,他说道,带着不易明了的微笑。 
 See: opaque
 - More examples
 - He had his reasons, although they were opaquely explained.
 - She will only say opaquely that things aren't as resolved as they might be.
 - This is a rather opaquely written account of the artist's life and work.