Move slowly, freezing in empty cell (5)
I believe the answer is:
crawl
'move slowly' is the definition.
(I've seen this before)
'freezing in empty cell' is the wordplay.
'freezing' becomes 'raw' (both can mean cold).
'in' indicates putting letters inside.
'empty' means to remove the middle letters.
'cell' with its middle removed is 'cl'.
'raw' placed inside 'cl' is 'CRAWL'.
(Other definitions for crawl that I've seen before include "Move as snakes do, or on hands and knees" , "Grovel" , "Move slowly (as a baby does?)" , "Scramble on all fours" , "Make no haste" .)