abatis
backdrop
background
barbed
barricade
barrier
block
bond
bondage
bound
cage
captivity
cell
circle
clip
close
close up
defence
encircle
enclosing
fence
fortify
gaol
gauze
grate
green
grille
guard
jail
lattice
meta
metal
metallic
net
netting
pattern
prison
railing
repeating
repetition
secure
separate
slavery
stockade
surround
trap
tresspass
up
wall
wire