Stop old flame fleeing from Dalek’s cry (9)
I believe the answer is:
terminate
'stop' is the definition.
(synonyms)
'old flame fleeing from dalek's cry' is the wordplay.
'old flame' becomes 'ex' (I've seen this in other clues).
'fleeing from' suggests deleting specific letters.
'dalek's cry' becomes 'exterminate' (catchphrase of the Daleks in the show Doctor Who).
'exterminate' with 'ex' taken away is 'TERMINATE'.
(Other definitions for terminate that I've seen before include "Cut short" , "Stop" , "Bring to an end" , "Put an end to, discontinue" , "Kill off" .)