Back intended to smother header from Newcastle (7)
I believe the answer is:
finance
'back' is the definition.
(thesaurus)
'intended to smother header from newcastle' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is present in the answer.
This explanation may well be incorrect...
(Other definitions for finance that I've seen before include "Public money" , "Supply funds" , "Support monetarily" , "Fund" , "Provide cash for" .)