1. A colloquial word used to express contrition or error.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• peccavy,
• oeccavi,
• leccavi,
• -eccavi,
• 0eccavi,
• pwccavi,
• psccavi,
• pdccavi,
• prccavi,
• p4ccavi,
• p3ccavi,
• pecavi,
• peeccavi,
• Pecahvi,
• Peccahvi,
• Peccavie,
• Pecchaevi,
• Peccova,
• Peccahvie,
• Pecchavi

The plural of the "Peccavi" can be the "peccavis".

The singular of the "Peccavi" can be the "Peccavi".