Bishop, say, presented with prize flower (9)
I believe the answer is:
buttercup
'flower' is the definition.
(thesaurus)
'bishop say presented with prize' is the wordplay.
'bishop' becomes 'b' (abbreviation used in chess).
'say' becomes 'utter' (I've seen this before).
'presented with' means one lot of letters go next to another.
'prize' becomes 'cup' (cup is a kind of prize).
'b'+'utter'+'cup'='BUTTERCUP'
(Other definitions for buttercup that I've seen before include "Common grassland plant, poisonous to livestock" , "Yellow-flowered grassland plant" , "Common yellow flower" , "Rich yellow wild flower" , "Meadow flower poisonous to cattle" .)