Antilocution is a term defined by psychologist Gordon Allport

Gordon Allport

Gordon Willard Allport was an American psychologist. Allport was one of the first psychologists to focus on the study of the personality, and is often referred to as one of the founding figures of personality psychology...

  in his book The Nature of Prejudice, 1954. Antilocution is defined as verbal remarks against a person, group or community, which are not addressed directly to the target. Generally referred to as "talking behind someone's back," the impact of this is often overlooked. However because antilocution creates an environment where discrimination

Discrimination

Discrimination is the prejudicial treatment of an individual based on their membership in a certain group or category. It involves the actual behaviors towards groups such as excluding or restricting members of one group from opportunities that are available to another group. The term began to be...

 is acceptable, it frequently progresses to other more damaging forms of prejudiced behavior. It's use is overshadowed by the more modern term Hate speech

Hate speech

Hate speech is, outside the law, any communication that disparages a person or a group on the basis of some characteristic such as race, color, ethnicity, gender, sexual orientation, nationality, religion, or other characteristic....

which has almost the same meaning.