Didn’t move away on leaving region (5)
I believe the answer is:
froze
'didn't move' is the definition.
(I've seen this in another clue)
'away on leaving region' is the wordplay.
'away' becomes 'fro' (I've seen this in another clue).
'leaving' is a deletion indicator.
'region' becomes 'zone' (zone is a kind of region).
'zone' with 'on' taken out is 'ze'.
'fro'+'ze'='FROZE'
(Other definitions for froze that I've seen before include "Didn't move" , "Became iced over" , "Stopped dead" , "Became immobilised" , "stopped moving altogether" .)