an abbreviation of "trigger warning". trigger warnings are meant to warn people of content in fan fictions that could be harmful or "triggering" to those who have dealt with situations such as abuse. fan fiction is tagged using various tws so that readers may prepare for or avoid certain content. sometimes cw, an abbreviation of "content warning", is used instead of or in addition to a tw. trigger warnings are usually inserted when the subject matter of a piece of work deals with things issues like drug abuse, mental illness, abuse, or extreme violence.