1) Cluttered place 2) Cluttered room 3) Dirty, cluttered place 4) Dirty, messy place 5) Disorderly place 6) Metaphor for disorder 7) Very cluttered place 8) Very untidy place 
The interconnections of a PCB before they are assigned to appropriate layers and Routed to avoid one another. (Slang derived from a 'tangled mess'!)