stegnuti

1. to tighten
   Stegni šraf još malo, klima se. — Tighten the screw a bit more, it's loose.
   Stegnuo je čvor i proverio konopac. — He tightened the knot and checked the rope.
2. to squeeze; to clench; to grip
   Stegla mi je ruku i rekla: „Hvala.“ — She squeezed my hand and said, 'Thank you.'
3. (of rules, control) to tighten; to crack down
   Vlada je stegla kontrolu na granici. — The government tightened border controls.
4. (stegnuti se; of muscles, a wound) to contract; to tighten; to close up
   Srce mi se steglo kad sam čuo vest. — My heart sank when I heard the news.
   Rana se stegla i počela da zarasta. — The wound closed up and started to heal.
5. colloq. (stegnuti se; of money) to cut back; to economize
   Ovog meseca moramo malo da se stegnemo. — This month we'll have to cut back a bit.

The imperfective counterpart is stezati.