bastion /bastˈyən or bast-i-ən/

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

• hard-a-lee
• hard and fast
• hard-and-fast
• hard-and-fastness
• hard as nails
• hard at it
• hardback
• hardbacked
• hardbacks
• hardbake
• hardbakes
• hardball
• hardballs
• hardbeam
• hardbeams
• hard-billed
• hard-bitten
• hardboard
• hardboards
• hard-boiled
• hard bop
• hard card
• hard cards
• hard case
• hard cases