Mea culpa is the admission or acknowledgement of making a personal mistake. Traditionally, it is used in the prayer The Confiteor in the Catholic Church. It is slowly making its way into contemporary everyday use.
Mea culpa is a Latin term translating literally into English as “through my own fault.” Perhaps because of its use in prayer, the term has been used in English for centuries. The first recorded use was in the late 14th century by Chaucer in Troylus, though it has likely been in use before this.
Some might argue that any use outside of prayer is improper, but as can be seen above, the phrase has been making its way into speech and the written word for hundreds of years. It is perhaps one of the less commonly seen Latin phrases in common or popular use, but, technically speaking, wouldn’t be incorrect or out of place in an informal context.
In a non-religious context, think of mea culpa as a fancy way of saying ‘my bad.’ Like most Latin phrases in English use, it is italicised. It can be used both as a noun and an interjection, although the former is more common. As a noun, it usually refers to a detailed and sincere apology. Examples of use in a sentence include:
“I forgot – mea culpa,” said Bob.
She wrote a long mea culpa on her blog to apologise to everyone she’d hurt.
The phrase can also be extended to mea maxima culpa, literally meaning ‘my most grievous fault.’