It's cock. Took a course with Andrew Appel; the heroic man did not flinch once when he said it over and over again during the semester. My favorite line of the course: "You're going to do your homework in COCK."
Reasonable people might disagree, but I think that what they say there doesn't answer the question at all. Cock means rooster in English too, after all, but somehow the name doesn't get used.