zatezati

1. to tighten; to pull tight
   Majstor zateže šrafove na vratima. — The repairman is tightening the screws on the door.
   Ne zateži konopac previše, pući će. — Don't pull the rope too tight, it'll snap.
2. colloq. (often + s/sa + instr.) to drag one's feet; to stall; to delay
   Firma već mesecima zateže s isplatom plata. — The company has been stalling on paying wages for months.
   Hajde, nemoj da zatežeš, reci šta je bilo. — Come on, stop stalling and tell me what happened.
3. (of relations) to strain; to make tense
   Nove carine dodatno zatežu odnose između dve zemlje. — The new tariffs are further straining relations between the two countries.
4. (of skin, muscles) to feel tight; to pull
   Koža me zateže posle sunčanja. — My skin feels tight after sunbathing.

The perfective is zategnuti.