Harangue over tax (5)
I believe the answer is:
orate
'harangue' is the definition.
(thesaurus)
'over tax' is the wordplay.
'over' becomes 'o' (cricket abbreviation).
'tax' becomes 'rate' (rate is a kind of tax).
'o'+'rate'='ORATE'
(Other definitions for orate that I've seen before include "Declaim or rant" , "Make a formal address" , "Spout" , "Make a lengthy speech" , "Deliver a speech" .)