Incite, say, unlimited agony (3,2)
I believe the answer is:
egg on
'incite' is the definition.
(synonyms)
'say unlimited agony' is the wordplay.
'say' becomes 'eg'.
'unlimited' means to look at the middle letters (discard the edges or 'limits' of the word).
The middle of 'agony' is 'gon'.
'eg'+'gon'='EGG ON'
(Other definitions for egg on that I've seen before include "Fire" , "Urge, impel" , "Press" , "'Incite, urge (3,2)'" , "Encourage to act" .)