ground·sill 
(groundsĭl′) also ground·sel (groundsəl, groun-)
(groundsĭl′) also ground·sel (groundsəl, groun-)n.
The horizontal timber nearest the ground in the frame of a building.
- counteract
- counteraction
- counteractive
- counteractively
- counterargument
- counterattack
- counterbalance
- counterblow
- counterchange
- countercharge
- counter check
- countercheck
- counterclaim
- counterclaimant
- counterclockwise
- counterconditioning
- countercoup
- countercultural
- counterculture
- counterculturist
- countercurrent
- countercurrently
- countercyclical
- counterdemonstration
- counterdemonstrator