Wear down the Queen with poetry (5)
I believe the answer is:
erode
'wear down' is the definition.
(I've seen this before)
'the queen with poetry' is the wordplay.
'the queen' becomes 'er' (Elizabeth Regina).
'with' is a charade indicator (letters next to each other).
'poetry' becomes 'ode' (I've seen this before).
'er'+'ode'='ERODE'
(Other definitions for erode that I've seen before include "Gradually wear away" , "'Deteriorate, wear away (5)'" , "Eat away" , "Grind down" , "Slowly remove" .)