Стан девушки был тонкий и гибкий. | The girl's waist was slender and lithe. |
Широкий пояс охватывал её стан. | The wide belt encircled her waist. |
NB When the word стан functions as a subject and does not have a descriptive modifier, the construction стан у + Genitive is often preferred to (a) and (b), above: | |
Стан у девушки был тонкий и гибкий. | The girl's waist was slender and lithe. |