This is a tank dress from Old Navy that looks like dark denim. It has a side zip but I never used it and just put it on over my head like a heathen. Stretchy back, open hips. Could fit a L or XL if your size is more in your hips/butt I think because of the stretch. Big boobs may be a no-go though. It's a cute dress that always made me feel like an imposter for some reason.