Solidifying position (7)
I believe the answer is:
setting
This clue is a double definition.
'solidifying' is the first definition.
(setting is a kind of solidifying)
'position' is the second definition.
(I know that setting is a type of position)
(Other definitions for setting that I've seen before include "Surroundings; hardening" , "musical version of poem" , "Musical version of song" , "Place where an event takes place" , "Going down (of the sun)" .)