Fancy knight brought in to give a speech (6)
I believe the answer is:
ornate
'fancy' is the definition.
(I've seen this before)
'knight brought in to give a speech' is the wordplay.
'knight' becomes 'n' (chess abbreviation).
'brought in to' means one lot of letters goes inside another.
'give a speech' becomes 'orate' (oratory is public speaking).
'n' inserted into 'orate' is 'ORNATE'.
(Other definitions for ornate that I've seen before include "Over-elaborate" , "Florid" , "Elaborate, flowery" , "Lavishly decorated" , "Ostentatious" .)