: a statement cautioning that content (as in a text, video, or class) may be disturbing or upsetting
Colleges across the country this spring have been wrestling with student requests for what are known as "trigger warnings," explicit alerts that the material they are about to read or see in a classroom might upset them or, as some students assert, cause symptoms of post-traumatic stress disorder in victims of rape or in war veterans. Jennifer Medina, The New York Times, 17 May 2014
Trigger warnings arose out of the psychological concept of Post-Traumatic Stress Disorder "triggers"—experiences or events that cause a trauma survivor to re-experience an incident, go into avoidance mode, or "numb out." While the theory evolved in the wake of the Vietnam War, the use of "trigger warnings" is very much a result of the feminist Internet, and the atmosphere of the 21st-century political climate. Sarah Seltzer, Flavorwire, 27 May 2015