sag out

A term used to define the undesirable appearance of a person's clothing or outfit.

Sagging out can be at it's most noticeable form when items of clothing can be seen as drooping, in combination with slumped posture, flat hair, loose pant legs (otherwise known as bootcut), and more generally, an unfitted article of clothing.

Did you see Simon Cowell? That was a sag out if I've ever seen one.