posrnuti

1. to stumble; to trip
   Posrnuo je na stepenicama i udario koleno. — He stumbled on the stairs and hit his knee.
   Konj je posrnuo, ali nije pao. — The horse stumbled but didn't fall.
2. (morally) to go astray; to fall from grace
   Svako može da posrne u životu. — Anyone can go astray in life.
   Posrnuo je kad se obogatio i postao bahat. — He lost his way once he got rich and became arrogant.
3. (of a team, company) to falter; to slip
   Tim je posrnuo u drugom delu sezone. — The team faltered in the second half of the season.
   Kompanija je posrnula posle krize. — The company faltered after the crisis.