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)

• shapelessness
• shapelessnesses
• shapelier
• shapeliest
• shapeliness
• shapelinesses
• shapely
• shapen
• shape one's course
• shaper
• shapers
• shapes
• shapeshifter
• shapeshifting
• shape up
• shape-up
• shape-ups
• shaping
• shapings
• shaps
• sharable
• sharawadgi
• sharawadgis
• sharawaggi
• sharawaggis