Speak about knight in flowery style (6)
I believe the answer is:
ornate
'in flowery style' is the definition.
(ornate can mean a fancy style)
'speak about knight' is the wordplay.
'speak' becomes 'orate' (orating is a kind of speaking).
'about' is an insertion indicator.
'knight' becomes 'n' (chess abbreviation).
'orate' going around 'n' is 'ORNATE'.
(Other definitions for ornate that I've seen before include "Excessively decorated" , "Elaborately decorated, perhaps overdone" , "Richly decorative" , "(Of literary style) complex and with unusual words" , "Rich in decorative detail" .)