Queen, say, reveals note (6)
I believe the answer is:
quaver
'note' is the definition.
(quaver is a kind of note)
'queen say' is the wordplay.
'queen' becomes 'qu'.
'say' becomes 'aver' ('aver' can be a synonym of 'say').
'qu'+'aver'='QUAVER'
'reveals' is the link.
(Other definitions for quaver that I've seen before include "Half-crotchet" , "Tremble; musical note" , "Tremble - half a crotchet" , "Shake; a short note" , ".Speak in a trembling voice" .)