struk

1. waist
   Pantalone su mi malo široke u struku. — My trousers are a bit loose at the waist.
   Ima veoma tanak struk. — She has a very slim waist.
2. (of a plant) stalk; stem; individual plant
   Kupila sam nekoliko strukova mladog luka. — I bought a few stalks of spring onion.
   Dodaj jedan struk celera u supu. — Add one stalk of celery to the soup.

"At the waist" is usually u struku.