propadati

1. (of a building, town, person) to decay; to fall into ruin; to go downhill
   Stara kuća godinama propada. — The old house has been falling apart for years.
   Posle razvoda je počeo da propada. — After the divorce he started going downhill.
2. (of a business, a plan) to fail; to go bust
   Male prodavnice propadaju jedna za drugom. — Small shops are going under one after another.
   Svi naši planovi stalno propadaju. — All our plans keep falling through.
3. (into snow, water) to fall through; to sink
   Noge su nam propadale u dubok sneg. — Our feet kept sinking into the deep snow.
4. (of food, things) to go to waste; to go bad
   Svake nedelje nam propada pola hleba. — Half a loaf of bread goes to waste every week.

The perfective is propasti.