la-di-da

interjection

1. (used as an expression of derision directed at affected gentility or pretentious refinement.)

adjective

2. affected; pretentious; foppish: a la-di-da manner.

noun

3. an affected or pretentious person.
4. behavior or speech characterized by affected or exaggerated gentility.

adjective

1. informal affecting exaggeratedly genteel manners or speech

noun

2. a la-di-da person

mocking of affected gentility, 1874, in derisive imitation of “swell” way of talking.