Recognised king was victorious over knight (5)
I believe the answer is:
known
'recognised' is the definition.
(thesaurus)
'king was victorious over knight' is the wordplay.
'king' becomes 'k'.
'was victorious' becomes 'won' (I've seen this before).
'over' says the letters should be written in reverse.
'knight' becomes 'n' (chess).
'won' in reverse letter order is 'now'.
'k'+'now'+'n'='KNOWN'
(Other definitions for known that I've seen before include "Famous" , "Acknowledged" , "In the public domain?" , "Within one's ken" , "Widely recognized" .)