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)

• bandshells
• bandsman
• bandsmen
• bandstand
• bandstands
• bandster
• bandsters
• band-stone
• band-string
• band-strings
• bandura
• banduras
• bandwagon
• bandwagons
• band-wheel
• band-wheels
• bandwidth
• bandwidths
• bandy
• bandy-ball
• bandy-bandy
• bandying
• bandyings
• bandy-legged
• bandyman