| shut in(verb, expression, phrasal verb, secure, block) |
| support(noun, verb, defend, defense, fortification) |
| answer(noun, verb, defend, defense) |
| backfire(noun, verb, defend, defense) |
| bank |
| bastion(noun, cover, keep, position, guard) |
| blockage(noun, help, open, disorder, block) |
| check(noun, verb, stop, trouble, control) |
| choke off(verb, phrasal verb, hindrance) |
| counterattack(noun, verb, defend, defense) |
| debar |
| difficulty(noun, disorder, block, weakness, burden) |
| dike(noun, verb, close, cover, secure) |
| embankment(noun, cover, position, block, bar) |
| intercept(verb, stop, close, halt, block) |
| moat(noun, defense) |
| mound(defense, elevation, fortification, wall, embankment) |
| prevent(verb, stop, close, check, halt) |
| protection(noun, support, cover, position, guard) |
| rail(block, prison, fence, wall) |