That's a name for a sleeveless t-shirt. I guess the idea is that it's worn by guys who beat their wives. Or looks like something that could be worn by guys who beat their wives. There's even something called a "shooter shirt," a sleeveless t-shirt with large armholes. According to the Wikipedia the name comes from the American South and the shirt is worn mostly by men as the large armholes could make women's breasts suddenly pop out.
So I'm wondering what a husband-beater would look like. Or a child fucker t-shirt. Or a murderer t-shirt. Note that what we accept and what we don't accept tells us lots about the culture we live in. Also makes feminazis humorless bitches.
Sigh. This is what I write when I should have my talons sharply on the day's hawt news items.