Remain perfectly still and go cold all over (6)
I believe the answer is:
freeze
'remain' is the definition.
(thesaurus)
'perfectly still and go cold all over' is the wordplay.
I cannot quite understand how this works, but
'over' could be 're' and 're' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for freeze that I've seen before include "Stand still!" , "Chill, sounds like decorative band" , "period of cold weather" , "Change liquid to solid through cooling" , "Economic measure - go rigid - refrigerate" .)