1 provide support for the truth or correctness of; make definitely valid (confirmed my suspicions; confirmed his arrival time).
2 (foll. by in) encourage (a person) in (an opinion etc.).
3 establish more firmly (power, possession, etc.).
4 ratify (a treaty, possession, title, etc.); make formally valid.
5 administer the religious rite of confirmation to.
Derivatives:
confirmative adj. confirmatory adj.
Etymology: ME f. OF confermer f. L confirmare (as com-, firm(1))
Useful english dictionary. 2012.