bastion /bastˈyən or bast-i-ən/

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

• bucketfuls
• bucketing
• bucketings
• bucket list
• bucket lists
• bucketload
• bucketloads
• buckets
• bones
• boneset
• bonesets
• bonesetter
• bonesetters
• boneshaker
• boneshakers
• bones of contention
• bone spavin
• bonetired
• bone turquoise
• bone-turquoise
• bone up on
• bone-weary
• boneyard
• boneyards
• bonfire