: to remove (someone) from a list of designated friends on a social networking website : unfriend
Facebook users may also choose to "defriend" any of their previously added friends, at which point that individual will have restricted access to the user's information if privacy settings are enabled. Rahul S. Chauhan et al.
Get rid of all memorabilia of your relationship and defriend your ex's friends and family on Facebook. Alexia Elejalde-Ruiz