1.nounAn official indicator that things will happen as planned.
"We will send you a written confirmation of your hotel booking."
2.nounA verification that something is true or has happened.
"The announcement in the newspaper was a confirmation of my suspicions."
3.nounA ceremony of sealing and conscious acknowledgement of the faith in many Christian churches, typically around the ages of 14 to 18; considered a sacrament in some churches, including Catholicism, but not in most Protestant churches.