linchpin /linchˈ or linshˈpin/

1. A pin used to keep a wheel on its axle
2. A person or thing essential to a plan, organization, etc (figurative)

• bedrooms
• bedroom tax
• bedrop
• bedropped
• bedropping
• bedrops
• bedropt
• beds
• Beds.
• bed-settee
• bed-settees
• bed-sheet
• bed-sheets
• bedside
• bedside book
• bedside books
• bedside manner
• bedside manners
• bedsides
• bedsit
• bedsits
• bedsitter
• bedsitters
• bedsitting-room
• bedsitting-rooms