Threshold
'threshold' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sill that I've seen before include "Slab at foot of window" , "Window edge" , "Underwater rock ledge" , "Shelf at the foot of a window" , "Horizontal timber forming the bottom of a framework" .)
'threshold' is the definition.
(I know that threshold can be written as verge)
This is the entire clue.
(Other definitions for verge that I've seen before include "Grass border along road" , "Grass edge to road" , "Border - edge" , "Side of road" , "Grassy road edge" .)