anti-defamation       
adjective [ before noun ]  formal uk/ˌæn.tiˌdef.əˈmeɪ.ʃən/ us/ˌæn.taɪˌdef.əˈmeɪ.ʃən/
 反诽谤的
intended or intending to prevent or deal with defamation (= the action of damaging the reputation of a person or group by saying or writing bad things about them that are not true)
  He said that anti-defamation laws should not be used to limit free speech. 他说,反诽谤法不应该用来限制言论自由。 
 Hundreds of incidents have been reported to the anti-defamation group. 
 - More examples
 - There was already an anti-defamation clause within the existing legislation, forbidding prejudice and discrimination against minority religious groups.
 - He defended the decision to include anti-defamation language in the document.