EDIT: I hate mixing up the little things. I've changed the post. If you didn't read it before today - you don't know if I messed up or not!
I guess I don't feel so inspired to write something long-winded about this word, so another short blog will have to do.
退く in context is usually used to mean "get out of the way" and with certain vocal connotation, it has the feeling of "get the hell out of the way."
If you look it up in a dictionary, it's going to give you the definition of "retreat, recede, or withdraw" depending on the dictionary. All those meanings are just fine and dandy, but you wouldn't use them in everyday conversation in your native language with someone close. It's better to envision the word springing up as siblings are arguing as the following example:
退いて！！! (that's easy eh?). Or you could say どっか行って！！！
I guess I might need to explain the どっか part as well. どっか is a contracted form of どこか (somewhere, some place, anyplace), and I can only really say that it's use kinda depends on you being in a bad mood. I wouldn't go so far as to say that it's guttural, but it's certainly not a word that your parents would be proud of you using because it isn't "proper." The only way that I know how to get the message across is to say that it's a slur along the lines of "hafta" where a "proper" grammarian parent would chastize with "have to" upon hearing which eyes are immediatly rolled and the word may be repeated as button-pushing necessitates.
So for today, a fighting-twofer.