Dream of the world are in decay: hint to your current life dissatisfaction, appetite for destruction.
Dream of eating rotten food: means your body will sick.
Dream of decay: suggests that your life is very decadent, without any vitality.
Dream of things are rotten: foretells that you will experience the wind and rain, will be born again.
Usually, dream of rotten represents dreamer of self in the spirit of negation.