“Incel” is a term that’s short for “involuntarily celibate.” The term took off as the name of a deeply misogynistic Reddit group comprised of tens of thousands of mostly young men that was rife with messages bashing women and condoning rape. Reddit eventually banned the group. In a twist of irony, Elle magazine reported that the term “incel” was first coined by a woman.

“Chads and Stacys” is 4chan slang for attractive, young and well-off white men and women. Members of the “Incel” community resent “Chads and Stacys” for what they believe to be an unfair ease of having casual sexual encounters with each other. In recent months, an alt-right offshoot known as “Chad Nationalism,” has attempted to court frustrated young men by peddling them white nationalist ideologies while providing them with encouragement and advice on obtaining a muscular “Chad” body. Activists in the “Chad Nationalist” movement often speak about drawing in attractive women who adhere to male-dominant “traditional” gender roles and will give birth to multiple children in order to combat changing ethnic demographics in western countries.

Elliot Rodger was a self-labeled “kissless virgin” who wrote a manifesto on “the cruelness of women” before murdering six people in Santa Barbara in 2014. Rodger had at times identified himself as an “incel,” placing him, as The Washington Post noted at the time, in “that corner of the Internet where boys will be boys, girls will be objects, and critics will be ‘feminists,’ ‘misandrists’ or ‘enemies.’”

(http://www.autoadmit.com/thread.php?thread_id=3959402&forum_id=2#35916190)