It is a device used to restrain roosters, of course. Roosters are in general violent so they have to be stopped from perpetrating their anger on innocent people. There is no other definition of this word on the internets, especially not on urbandictionary.com, so don't even think to look there or be suspicious of my generously provided definition because I AM VERY IRASCIBLE IF SOMEONE DISSES MY WORDS.
Don't diss the words.
"Words are deeds." - Wittgenstein