To destroy or mar the face or external appearance of; to disfigure; to injure, spoil, or mar, by effacing or obliterating important features or portions of; as, to deface a monument; to deface an edifice; to deface writing; to deface a note, deed, or bond; to deface a record.

To destroy; to make null.

mar or spoil the appearance of; "scars defaced her cheeks"; "The vandals disfigured the statue"

deface a building facade, for example

To place a BADGE on a flag.