Often used in place of "fuck". Though it does sound quite dirty, is considered more polite--only because the word is unheard of outside Billings, Montana.
May also be used in place of "joking", or "kidding".
when one takes his flacid cack and smackes it across the face of another... possiblyleaving an indentation or some sort.
Jerome whipped his monsterous cack out of his "sean john" trousers and graciously fadonk'd oprah after learning that she had cheated on him with his own father.