One who swills cock. Best used when describing someone who is displaying traits of a "cocksucker", with a bit more zest. Can also be used to describe a female (or male if your into that kind of thing) who goes above and beyond the norm when giving head. You know, the kind of girl that not only takes the whole shaft, but manages to stuff your scrotum into her mouth as well.
"Not only did he pinch a gram out the nickel bag I had him get for me, he had the nerve to ask me to smoke him up too. And he tried to keep my change by telling me he already gave it to me. That cockswiller is going to get his cranium cracked"
"I couldn't believe it, this girl is a total bookworm, 4.0 student, quiet as a mouse, active participant in church... just when im thinking she could get any more boring, she takes my cock out and just starts inhaling it, balls deep, gagging and everything. She was a true cockswiller to the extreme"
N. A person guilty of swindling cocks, resulting in undesired sexual attention (usually after intercourse). A rare accusation, but feasible depending on the gender of the people arguing the matter. Ex. A gay couple: the pitcher may accuse the catcher of "cock swindling", meaning that the catcher stole the pitcher's cock after sex when he didn't want to fuck around.