Avoid Anne Boleyn’s fate (4,3)
I believe the answer is:
head off
'avoid' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for head off that I've seen before include "Turn away" , "Deflect from a path" , "Intercept - at the pass?" , "result of execution?" , "like Robespierre?" .)