bastion /bastˈyən or bast-i-ən/

1. A kind of tower at the angle of a fortification
2. A defence, defender (figurative)

• watered
• watered-down
• water elder
• water elders
• water engine
• water engines
• water equivalent
• water equivalents
• waterer
• waterers
• waterfall
• waterfalls
• water fern
• water ferns
• water-finder
• water-finders
• water flag
• water flags
• water flea
• water fleas
• water flies
• water flood
• waterflood
• waterflooding
• water floods