A confession is an admission of guilt, fault, or a mistake.
You’ve probably seen TV shows or movies where a detective says to a suspect "Confess!" The detective is trying to get a confession, which is a statement that admits some type of guilt. "I killed the mayor!" is a confession. "I forgot your birthday" is a confession. In some religions, confession is a sacrament where people admit their sins and seek forgiveness. When people have something painful to admit, they often start by saying, "I have a confession to make."
Primary Meanings of confession
an admission of misdeeds or faults
a public declaration of your faith
n an admission of misdeeds or faults
n the document that spells out the belief system of a given church (especially the Reformation churches of the 16th century)
the document drawn up in 1555 to defend the catholicity of Lutheran doctrine and to justify innovations in Lutheran practice; is still in effect today