A dress worn with a sweater or t-shirt on top to make it look like a top and a skirt.
Done with dresses which have a particularly ugly neckline.
Popularised by and named after the UK trend setter Gert
Person 1: I don't know why I wore this dress today, the straps are so fugly
Person 2: Yeah but the hem is nice. Why don't you turn it into a Gert skirt?
Person 1: Good idea, can I borrow your sweater?