Decay
[1] The process of decaying; a gradual fragmentation into its constituent parts / components.

Decay
[2] Physics: the spontaneous splitting of an atomic nucleus.

Wilderness (n.)
-an uncultivated, uninhabited, and inhospitable region
similar: wilds, wastes, uninhabited region, inhospitable region, uncultivated region
- a neglected or abandoned area.
"the garden had become a wilderness of weeds and bushes”
similar: wasteland, neglected area, abandoned area, no-man's-land
a position of disfavour, especially in a political context.

"the man Who led the Labour Party out of the wilderness”