The Brief: Cuck, a shorthand for "cuckold" is a popular insult used by members of the Alt-Right.
“Cuck” is a derogatory term with sexist connotations and racist origins. It stems from the word “cuckold,” which refers to a man whose wife has sex with another man. Historically, and through its portrayal in pornography, the term cuckold implies a white man who is “emasculated” when his wife cheats on him with a black man.
Variations of the term include “cuckservative” – a conservative man who doesn’t support Trump – and “liberal cuck”- a weak liberal man. Supporters of the Alt-Right use this term to equate white masculinity and sexual dominance with strength and power. By insulting the masculinity of liberal and non-Trump supporting men, the Alt-Right suggests that their movement is the manliest and that women’s political opinions are not important.