Cuck is a word used by alt-righters to describe anybody weak, specifically a conservative who compromises some of their values to the "liberal agenda". This term, popularized on deeply conservative message boards in election-season 2016, derives from the much older word cuckold, the "husband of an adulteress" and a type of person typically stereotyped as weak, because they couldn't keep a partner. Cuckold has quite the diverse history. In Middle English, it was spelled either as kukewald or cokewold. Both of these alterations come from Old French cucuault, which is a formation off of cocu, the word for "cuckoo" (because the female cuckoo is known for changing mates) and the Germanic suffix -ault, which had pejorative connotations. Cocu is onomatopoeic in origin, as it's meant to be imitative of the actual cry of a cuckoo. -Ault comes from Frankish walda, meaning "authority".
Adam Aleksic, a leading contender for valedictorian of his high school, is a 211-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and probably isn't spying for the Kyrgyz government.
The Etymology Nerd