žarište

1. (of fire, disease) seat; source; centre
   Vatrogasci su brzo pronašli žarište požara. — The firefighters quickly found the seat of the fire.
   Ova škola je postala žarište zaraze. — This school became the source of the infection.
2. hotbed; flashpoint; hot spot
   Taj region je i dalje žarište sukoba. — That region is still a flashpoint of conflict.
   Granica je postala novo krizno žarište. — The border has become a new crisis hot spot.
3. (in optics) focus; focal point
   Sočivo skuplja sunčeve zrake u jednom žarištu. — The lens gathers the sun's rays at one focal point.

Most often used in phrases like žarište požara, žarište zaraze, žarište sukoba.