overgrowth
This term carries a strong sense of neglect or lack of control. It suggests a state where nature has reclaimed a space, evoking images of tangled vines, wild weeds, and hidden pathways. It is frequently used in landscaping and urban exploration to describe the transition from a managed environment to a wild one. In medical or biological contexts, the word shifts from a visual image of nature to a clinical concern. Here, it implies an abnormal or pathological proliferation of cells that disrupts the balance of an organ or system, carrying a negative and urgent connotation.
Countable when referring to a specific area of wild vegetation (an overgrowth of ivy). Uncountable when referring to the general state of being overgrown (the overgrowth in the backyard).