What does the Latin phrase "mea culpa", used in the Roman Rite, mean?

Through my fault, through my fault, through my most grievous fault…

Thanks for the correction. I always thought the phrase was nominative.

CyanJaguar62, OMG!! That same phrase that stuck with you also stuck with ME!! In fact, it’s the only phrase , I remembered! 😂

CyanJaguar62, they chanted or sung it. Mesmerizing

They still said the Catholic mass in Latin when I was a kid and that phrase stuck with me. Kinda like "ecum spiri tu tu o" (don't know how it was actually spelled) because it sounded like a phone number

No, it literally means my (mea) fault (culpa). If you want to add the word "through" you need some form of via (through).