For Edith, cry out for a day of victory! (6)
I believe the answer is:
cavell
'a day of victory' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'for edith cry out' is the wordplay.
'for edith' becomes 've' (I can't justify this - if you can you should give a lot more credence to this answer).
'cry' becomes 'call' (synonyms).
'out' is an insertion indicator.
've' placed within 'call' is 'CAVELL'.
'for' is the link.
Can you help me to learn more?
(Other definitions for cavell that I've seen before include "Edith -, nurse executed in 1915" , "Wartime nurse" , "WWI nurse executed by Germans" , "Nurse Edith ...... was heroine of WW1" , "I was shot by the Germans" .)