Definition & Meaning of "lah-di-dah"

What is the origin and context of use of 'lah-di-dah'?

The exact origin of "lah-di-dah" as an interjection is not precisely documented. However, it likely originated as an imitation of upper-class British speech patterns or as a representation of a nonchalant, carefree attitude. It is often used in situations where someone is perceived to be flaunting their social status, wealth, or sophistication in an ostentatious or affected manner to lightly mock or sarcastically comment on behaviors or attitudes that are seen as overly snobbish or self-important.