'mea culpa' definitions:

Definition of 'mea culpa'

(from WordNet)
noun
An acknowledgment of your error or guilt

Definition of 'mea culpa'

From: GCIDE
  • Peccavi \Pec*ca"vi\ [L.] I have sinned; -- used colloquially to express confession or acknowledgment of an offense; -- used rarely, superseded by the approximate equivalent mea culpa. --Aubrey. [1913 Webster +PJC]