to remove the classification from (information, a document, etc.) that restricts access in terms of secrecy, confidentiality, etc. Compare classification(def. 5).
de·clas·si·fy (dē-klās'ə-fī') tr.v.
de·clas·si·fied, de·clas·si·fy·ing, de·clas·si·fies To remove official security classification from (a document). de·clas'si·fi'a·ble adj., de·clas'si·fi·ca'tion (-fĭ-kā'shən) n.