The inspiration for and namesake of the U.S. Army's M-1A1 Main Battle Tank. In urban use, it is a discreet way of describing a woman with a large rear end. This is used in lieu of the phrase Tank Ass. It is advantageous because unless the woman has a knowledge of American military history she will be none the wiser.
Wow, that's quite a butt she has on her.
Yes, she's quite the General Abrams.