porasti

1. (of a person, plant) to grow; to grow up
   Kad porasteš, shvatićeš zašto sam to uradio. — When you grow up, you'll understand why I did it.
   Paradajz je mnogo porastao za nedelju dana. — The tomatoes grew a lot in a week.
2. (of prices, amounts) to increase; to rise; to go up
   Cene struje su ponovo porasle. — Electricity prices have gone up again.
   Temperatura će sutra porasti do trideset stepeni. — Tomorrow the temperature will rise to thirty degrees.

Perfective of rasti; in the sense 'grow up' it is close to odrasti.