classified /ˈklæsəfaɪd/adjective 3noun 1forms 3 adjective3 •Sorted into classes or categories. •marked by a government as secret, so that only people with permission may see itWe do not discuss specific interrogation techniques because they are classified information. •Not meant to be disclosed by a person or organization.I won't say who I'm going to the prom with; that's classified. noun1 •(informal) A classified advertisement in a newspaper or magazine.He ran a classified for the tools he wanted to sell. formsclassifieds · more classified · most classified