Solidifies (4)
'solidifies' is the definition.
(I've seen this in another clue)
This is the entire clue.
'solidifies' is the definition.
(setting is a kind of solidifying)
This is the entire clue.
(Other definitions for sets that I've seen before include "Classes" , "Scenery etc. of 11 across productions" , "Places" , "Units of play in tennis" , "Major divisions of tennis match" .)