adversity
bars
boundary
bovine
brass
calf
chain
concepts
connection
dirty
door
farming
farmland
furniture
grunge
industrial
key
link
lock
manual
metallic
occupation
padlock
password
prison
prisoner
private
professional
protection
rust
rusty
safe
safeguard
safety
secrecy
secure
security
separation
sepia
silver
steel
system
tool
waste
work
worker
workshop