As with wifebeater, the name comes from the absence of sleeves, which allows the wearer to beat her boy (or perhaps any boy) unencumbered. This usage was first documented at the Goatwhore merchandise table during their 2012 tour.
After seeing the band's set, she wanted to get their boybeater, but they only had them in large.
Bruce saw Tony walking with all of his seven children and said “ Hey Tony, bring those little bambeaners over here, so I can teach them how to play softball!”
The ability girls and women have developed to hold several items at once in one hand. The skill has been developed due to the lack of pockets in women's clothing.
I thought she'd need multiple trips to carry her phone, keys, wallet, and Starbucks to her car since she needed the other hand to open the door, but she used her impressive girl grip to carry everything in one hand.