lynch·pin 
(lĭnchpĭn′)
(lĭnchpĭn′)n.
Variant of linchpin.
- special delivery
- special education
- special effect
- special forces
- special interest
- special-interest
- specialism
- specialist
- specialistic
- speciality
- specialization
- specialize
- specialized
- special jury
- Special K
- special legislation
- specially
- special master
- special-needs
- special needs
- specialness
- Special Olympics
- special operation
- special operator
- special pleading