In classical Chinese, what word means the back of a beautiful woman? (Don't say something that is known all over the world, such as Meitu)

The chickens crow outside and the bride wears strict makeup.

Embroidered skirts follow me, everything is four or five.

Step on your feet and shine on your head.

If the waist is flowing, Su Wan will listen to the bright moon.

Fingers like cutting onion roots, mouth like pearl Dan.

Exquisite and exquisite, unparalleled

Just beside the point! Excellent artistic conception!