Prize fighting in our era (5)
I believe the answer is:
award
'prize' is the definition.
(I know that prize can be written as award)
'fighting in our era' is the wordplay.
'fighting' becomes 'war'.
'in' means one lot of letters goes inside another.
'our era' becomes 'AD' (Anno Domini, in the year of our Lord).
'war' going within 'ad' is 'AWARD'.
(Other definitions for award that I've seen before include "Give, as an honour" , "Honour, accolade." , "medal, perhaps" , "Honour, prize" , "Tony, for example" .)