comes fromt he word "hater" and "friend"-combined it makes "frader"--a "frader" is someone who is your friend but secretly hates you. Usually one will never know who is or is not a "frader". You should just assume that they are out there, out to get you and you should wach your back at all times due to these "fraders"
Used in a sentence: "Oh I hate that bitch, I bet she is a 'frader'"
In a real life situation: Amy and Susie have been friends since thay were little, they arent too fond of each other but they both pretend to like one another. Then Amy found out that Susie is going out with Amy's x-boyfriend. Amy is pissed but pretends everything is cool.