la-di-da, lah-di-dah /ˌlɑː diː ˈdɑː/ adjectiveadj informal used to describe someone’s behaviour when you think they are talking and behaving as if they consider themselves better than other people 装腔作势的,装模作样的,做作的 SYN snobbish a la-di-da attitude 装腔作势的态度
Origin la-di-da (1800-1900) Copying the speech of upper-class people