peccavi (peh-KAH-vee) n. an admission of sin; a confession of guilt.
This word is a direct import from the Latin word peccavi ("I have sinned"), which is the first person singular perfect tense of peccare ("to sin"). One might use this term as a replacement for - or in conjunction with - the more familiar mea culpa ("my fault").
Scholar Mark Burnyeat once recounted for the New York Times a historical use of peccavi by British admiral Sir Charles Napier:
The fighting in the 1840s was at a time of British expansion in India. Nevertheless, there were those in Britain who doubted the wisdom of too rapid an advance, and in particular, the capture of the province of Sind, which was thought likely to lead to an overextension of lines of communication. Napier was therefore under express orders not to capture the territory. Once he discovered, however, how little resistance there was, he took the province with ease. ''Peccavi'' therefore meant both ''I have Sind,'' and ''I have sinned'' - perhaps a perfect pun.