abstract
arrest
background
barb
barbed
barbwire
barrier
border
boundary
cage
cell
close
concept
cord
crime
criminality
custody
danger
dangerous
detail
deterrent
element
enclose
guard
iron
jail
macro
metal
object
old
paper
part
pattern
prevent
prickle
prickly
prison
prohibited
protection
section
sharp
spike
spiky
steel
thorn
thorny
twisted
white
wire