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)

• wooed
• wooer
• wooers
• woof
• woofed
• woofer
• woofers
• woofier
• woofiest
• woofing
• woofs
• woofter
• woofters
• woofy
• wooing
• wooingly
• wooings
• wool
• wool ball
• wool balls
• wool-bearing
• wool card
• wool-carder
• wool-carders
• wool-carding