barb
barbed
barbs
barbwire
boundary
business
close
closeup
confine
confinement
constrain
contain
control
danger
defend
detail
enforcement
exterior
fence
fencing
field
guard
hazardous
imprison
imprisonment
in
incarcerate
industrial
industry
jail
keep
legal
limit
metal
nobody
object
outdoor
outside
prison
protect
protection
punish
restrain
rusty
safe
safeguard
secure
security
sharp
space
spiky
up
wire
wires