Today's word is:
An admission of sin or guilt.
From Latin 'peccavi' which literally means 'I have sinned.'
It gave rise to the most witty multilingual pun of all time. In 1843, when Sir Charles Napier sent a preliminary dispatch of a single word: peccavi. The reason? His military victory and conquest of the province of Sind (now in Pakistan). His message - "I have Sind."