I heard it on a radio station once and read it in "The Devil Wears Prada". I got curious.
What is a wife-beater?!
Wikipedia: A-shirt, a sleeveless undershirt.
About: a thin, ribbed tank originally worn by men as underwear. Men who wore it by itself as a shirt projected a low-class look (hence the "wife-beater" moniker). Although they started out as simple undershirts, slowly people began wearing them alone and they've become a favorite of celebs - from SJP to Paris Hilton (she likes to pair them with minis).
Online Slang Dictionary: a sleeveless undershirt. Origin: before wearing a wife-beater as one's only shirt became a popular style, the stereotype existed that they were worn primarily by alcoholics or people who were too poor to buy outer shirts. One stereotypical American image of an alcoholic is someone wearing an undershirt and beating their wife.
Now, I know! I won't get shocked anymore when I hear someone say he/she is wearing a wife-beater.