I think he is being 'dishonest' [='untruthful'] about what he knows.
They have been running their business 'dishonestly'.
I think she answered our questions 'dishonestly'.
(..) Oh. Cersei approached me. How worried your sister is about her. Making honest feelings do dishonest work is one of her many gifts. It was difficult for her to hide her true intentions. It is rare to meet a Lannister (..)2014 TvShow: Game of Thrones Title: Mockingbird Season: 4 Episode 7