1. A bruhment spoken by a boomer. The rules of bruhment still apply here, only now if the person committing the actual bruh moment is over 39, it is officially a booment.
2. An extremely powerful boomer moment. You know these when they happen, so you must act appropriately.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.