Uni ensured Head left without cover (9)
I believe the answer is:
uninsured
'head left without cover' is the definition.
I can't judge whether this definition defines the answer.
'uni ensured' is the wordplay.
'uni' becomes 'un' (I can't explain this - if you can you should believe this answer much more).
'ensured' becomes 'insured' ('insure' can be a synonym of 'ensure').
'un'+'insured'='UNINSURED'
Can you help me to learn more?
(Other definitions for uninsured that I've seen before include "Being without cover" , "with no policies" , "Not covered against loss" , "Not covered for losses" .)