From Longman Dictionary of Contemporary Englishconfirmedcon‧firmed /kənˈfɜːmd $ -ɜːr-/ adjective → a confirmed bachelor/atheist/vegetarian etc
Examples from the Corpus
confirmed• The Commissioner of Inland Revenue made and confirmed assessments on the taxpayer for those years in respect of the profits from sub-licensing the films.• The confirmed hard left on the executive is now reduced to two: Tony Benn, and Dennis Skinner.• Teachers are not required to give a confirmed level for a pupil at any one moment during the key stage.• But he was a confirmed teetotaller. 